Whole story. I'm te house staff. Even after the disastrous cnn debate against former president donald trump and the growing calls from democrats for him to pass the torch, biden seemed dug in. So the question is, what finally changed his mind? over the next hour, cnn's pamela brown examines the rise and fall of candidate joe biden from his motivations for running against donald trump to the final days and hours before his historymaking decision. [music playing] pamela brown (voiceover): it was summer 2017, joe biden was out of the vice presidency, out of washington dc, and in his home state of delaware. Evan osnos: joe biden found himself in a place he hadn't been in his entire adult life, frankly. His politics had defined his identity, and now all of a sudden, he was a man without a purpose. Jeff zeleny: it was always hanging over the question, would he get back in and run? jill biden: every single day, would come up to me at work or in the grocery store or the pharmacy, people on the street, strangers that i didn't even know would come up and say, you have to talk your husband into running. He has to run. He has to run. Pamela brown (voiceover): and then came the unite the right rally in charlottesville, virginia. Crowd: jews will not replace us! pamela brown (voiceover): then the president's reaction from trump tower in new york city. Donald trump: you also had people that were very fine people on both sides. Pamela brown (voiceover): biden was watching. Jill biden: joe thought, we have to have change. We have to have change in this country. Kate bedingfield: i remember him calling me and saying, are you watching what's happening in charlottesville? are you seeing this? i remember he said to me that afternoon, i want to say something about this. Pamela brown (voiceover): what would follow, a chain of events that would propel biden closer and closer to the presidency. Van jones: well, really, nobody thought biden was going to be a factor in 2020. Part of the reason obama picked him was because he was already in his 60s in 2008. So it's like this guy is not going to be around to get in the way of the rest of the party. And i think charlottesville was such a shock to people to see a president that was having a hard time forthrightly condemning something that most people just would automatically say no to. And i think it really bothered i think it bothered biden. Pamela brown (voiceover): so he did what he does with all big decisions. Evan osnos: biden turned, as he always has, to his most trusted core advisors, an unchanging group in many respects. Kate bedingfield: i mean, a lot of the discussions that we had in 2017 and 2018, as he was contemplating running, biden was really focused on if i'm going to get in this race, i'm going to be very clear about the fact that i believe the stakes are no less than a battle for the soul of our nation. Jill biden: our grandchildren came to joe and said, pop, we've all thought about it. You have to run. You have to run. You have to change things. Pamela brown (voiceover): but that change did not come quickly. It would take almost two years for biden to officially announce. Kate bedingfield: it was pressure from outside. There was the expectation, the waiting, the anticipation. What's he going to do. Jeff zeleny: every biden decision takes a long time. That's how he's made decisions in the senate. It's how he made decisions in the vice presidency, and certainly on his own political future. Pamela brown (voiceover): some believe he was still stung by the pressure back in 2016 to step aside and make room for hillary clinton. Evan osnos: joe biden was also seething, frankly, about having not been able to run in 2016 against donald trump. He had been coaxed out of the race, nudged out of it by barack obama and other powerful figures in the democratic party. Van jones: i think that bothered biden. I think biden felt that he had promised his son that he was going to run and he didn't do it. Joe biden: that's why today i'm announcing my candidacy for president of the united states. Jeff zeleny: when biden finally got into the race, there was excitement in some quarters of the democratic party, but there was also some apprehension. Evan osnos: a lot of people thought that joe biden was a voice from the party's past. He wasn't their idea of what the party's future could be. Bernie sanders: thank you, new hampshire. Subject 1: joe biden was on the side of the credit card companies. It's all a matter of public record. Van jones: people were excited about other candidates. Subject 2: there's a lot of people who are concerned about joe biden's ability to carry the ball all the way across the end line without fumbling. Van jones: it just seemed like yesterday's guy clinging the glory. And so the circle around biden was pretty small. His campaign was pretty small. There weren't big crowds. Pamela brown (voiceover): and there weren't big wins either. Anderson cooper: it's the disappointment for biden currently running fourth. Pamela brown (voiceover): the first two democratic primaries, biden placed fourth in iowa's caucuses, fifth in new hampshire. Evan osnos: he was really on the cusp of failing out of the race. In fact, he was so close to the end that one of his advisors said, you need to begin to prepare to have some money in the bank account in case we need to pay people for their severance and to close down the offices. Kate bedingfield: that was a very tough week. We were in new hampshire in that week. We were staying at a hotel in nashua, and the power went out in the hotel. We had candles in our rooms because there was no power in the hotel. There was some gallows humor around that. So it was tough moment, but there was a lot of faith in the strategy. Pamela brown (voiceover): that strategy win south carolina. And critical to that, the support of representative jim clyburn the two had met decades earlier. Pamela brown: did he talk to you about his dreams, ambitions, desires to be president one day? jim clyburn: well, it was very clear in that first meeting. Pamela brown (voiceover): they developed a close relationship and bonded. So in june of 2019, biden came calling for clyburn support, as did 21 other candidates at the representatives famous annual fish fry. After, clyburn rushed home to talk to his wife, emily, who was very sick. Jim clyburn: and she said to me that night, she says, i don't care how many people are running. I don't care how many are close friends of ours. If we want to win this election, we better nominate joe biden. And this was in may 2019. She passed away in september. [music playing] pamela brown (voiceover): just over five months later jim clyburn: i'm voting for joe biden. Van jones: you got to give clyburn credit because it's been easy to say, well, we're just going to go for cory booker, he's black. We're going to go for kamala harris, she's black. Black voters said, who can stop bernie and who can stop trump? and in that calculation, it was joe biden. And nobody saw it coming. Jeff zeleny: that really sealed joe biden's presidential candidacy. South carolina rescued him without a doubt. Anderson cooper: sweeping blowout win for the former vice president, joe biden. Joe biden: my buddy jim clyburn, you brought me back. Van jones: biden goes from being a marginal joke to being a juggernaut in south carolina because of jim clyburn. Joe biden: this is a man of enormous integrity. Kate bedingfield: having this moment where you just come roaring back in a way that's kind of bigger and stronger than people imagined was even possible. That feeling is so euphoric. Evan osnos: it was amazing how quickly things came together. Candidates dropped out of the race and democrats were so focused on trying to make donald trump a one term president. David urban: i expressed some concern to the folks in the campaign, different people, even the president himself, that joe biden was a much more formidable candidate than bernie sanders. Pamela brown (voiceover): donald trump went on the attack. Donald trump: they're going to put him into a home and other people are going to be running the country. Pamela brown (voiceover): he took on biden's age, despite being less than four years younger. Evan osnos: one of the ways he addressed was that he came up with a kind of language of it. He would say, i want to be a bridge to a new generation. The implication was, the suggestion was that he probably wouldn't serve two terms, but he never came out and said that directly. Pamela brown (voiceover): on august 17, almost three years to the day after the charlottesville rally that brought biden into the 2020 race. Joe biden: it's a great honor and humility. I accept this nomination for president of the united states of america. Pamela brown (voiceover): he accepted the democratic nomination. Joe biden: it was a wakeup call for us as a country. And for me, a call to action. I can never remain silent or complicit. I said, we're in the battle for the soul of this nation. And we are. Pamela brown (voiceover): biden would go on. Polls would show to beat trump in crucial presidential debates. Joe biden: the question is donald trump: just as radical left. Joe biden: will you shut up, man. Donald trump: listen, who is on your list, joe. ? who is on your list? jake tapper: gentlemen, i think we have ended up donald trump: to pack the court. Pamela brown (voiceover): and then on election day 2020 at the ballot box. Anderson cooper: biden is leading in nevada. But the math right now has biden leading in arizona. Cnn projects joseph r. Biden jr. Is elected. Pamela brown (voiceover): he wins the presidency a longtime dream fulfilled. But the opponent he defeated in this election refuses to go away. Donald trump: this was a massive fraud. This should never take place in this country. [music playing] do solemnly swear. Joe biden: i, joseph robinette biden jr. , do solemnly swear. John roberts: that i will faithfully execute. Joe biden: that i will faithfully execute john roberts: the office of president of the united states. Joe biden: office of president of the united states. David chalian: president biden obviously inherited the presidency at a very trying time. Most americans did not yet have a vaccine, so the pandemic was still raging. The economy was still reeling because of the pandemic. [music playing] joe biden: i said i intended to get 100 million shots in people's arms in my first 100 days in office. Tonight, i can say we're not only going to meet that goal. We're going to beat that goal. David chalian: americans were getting checks from the government to help them through the economic calamity that the pandemic had caused. So that was sort of a high water mark for joe biden. Joe biden: today, i signed into law the american rescue plan, an historic piece of legislation that delivers immediate relief to millions of people, includes $1,400 in direct rescue checks, payments. Pamela brown: and what about the infrastructure bill? franklin foer: infrastructure is perhaps the least sexy word in the english language, but it is so important to our ability to maintain our economic competitiveness and our national greatness. And the fact that was all crumbling and that we hadn't made these important investments for generations, was a big deal that he was able to reverse that and to do it in a way that was not just ramming it through congress. [applause] david chalian: joe biden was able to put together a bipartisan coalition of lawmakers and successfully pushed through an overwhelming infrastructure bill that could transform roads, highways, airports, and all the other pieces of america's infrastructure in a pretty substantial way. Pamela brown (voiceover): like any presidency, biden's has also had its bad moments, especially the chaotic withdrawal of troops from afghanistan. Nicole malliotakis: the 13 american service members are the first american troops to be killed in afghanistan, in fact, in 18 months. And it's been such a tragic and sad week for the united states of america. But we can't say that this was unpreventable. I believe there were a lot of horrific decisions that were made one after another that have led to where we are today. And it's extraordinarily unfortunate. Pamela brown (voiceover): a more lasting problem for president biden, the effects of which still linger m is high inflation caused, at least in part by all the money that the american rescue plan put into the economy. Subject 3: grocery prices went up. Gallon of milk was $1. 99. Now it's $2. 79. Van jones: joe biden trying to respond to the real pain of people coming out of covid, and the built up demand in our party for more aggressive government action put that fuel on a fire that just turned into a wildfire of inflation. Pamela brown (voiceover): there would be one issue, one concern that biden could not solve with legislation or an executive order. And that was his age. Van jones: he started looking different. He started walking different. And he started talking worse. And people started getting worried. Joe biden: i'm sure that the third world excuse me, the third world van jones: it was like this unspoken rule that you weren't supposed to say it, that you could see it, but you couldn't say it. And axelrod kind of broke the seal on that. David axelrod: he had strong support among democrats, but there were concerns about his age. And i was one of the people who expressed some of those, just as an electoral issue. Pamela brown (voiceover): two years ago, david axelrod told the new york times quote, the presidency is a monstrously taxing job, and the stark reality is the president would be closer to 90 than 80 at the end of a second term, and that would be a major issue. David chalian: and so those images of him tripping up the stairs of air force one or falling over a sandbag at that graduation at the air force academy, those were high profile public moments on camera, and his political opponents seized on him. Now, his aides also made adjustments because of them. So he started using the shorter steps to get up into air force one instead of the long steps to the top of the plane. He started wearing different shoes to try to stabilize his walks in public a bit more. Joe biden: good. Almost morning. Pamela brown (voiceover): president biden's team would schedule a few interviews or press conferences, fewer than any other recent president. Mj lee: there is the chance that the president could misspeak or make a mistake, and that's clearly something that white house advisors had become really sensitive to. [applause] pamela brown (voiceover): the president's aides went to great lengths to control what the public saw. Mj lee: for example, the white house rarely had the president doing public events early in the morning or late in the evening. Joe biden: thank you. Thank you. Pamela brown (voiceover): and yet, in 2023, despite the signs of aging, democrats had lined up behind biden as their 2024 candidate. Joe biden: when i ran for president four years ago, i said, we're in a battle for the soul of america. And we still are. Pamela brown: he announces that he is running for reelection. Seth moulton: to be honest, there were people who reached out to me, some people closer to biden than i am, who expressed concerns. I wasn't quite sure what to do. Jeff zeleny: so many private whispers about, is joe biden strong enough to win a second term? but publicly near silence. Really the wagons were circled from the very beginning, from the corridors of the west wing to the campaign headquarters in wilmington, delaware. So the party apparatus, to the extent that still exists, was really all behind joe biden. I mean, it's the power of incumbency in every way kept a primary from happening. Pamela brown (voiceover): but as this campaign wore on, it became increasingly difficult to ignore biden's physical and mental challenges. And february telling a story about current french president macron, biden said the name of a previous leader of france. Joe biden: and made iran from germany i mean, from france looked at me and said said you know pamela brown (voiceover): and he called egyptian president abdel fattah elsisi the leader of a different country. Joe biden: the president of mexico, elsisi did not want to open up the gate. Chris wallace: let's kick off with president biden bucking a super bowl tradition again, turning down an invitation from cbs for a pregame interview. David axelrod: that's like a layup for any president to do. You get a huge audience. So the fact that they turn that interview down was really a concern to a lot of people. I think that set alarm bells off in a lot of places. Mr. Speaker, the president of the united states. [cheers] pamela brown (voiceover): then in march, biden gave a state of the union speech, many described as a show of strength, seemingly reassuring some democrats. Joe biden: and i've been told i'm too old. Whether young or old, i've always been known i've always known what endures. I've known our north star. The very idea of america is that we're all created equal and deserves to be treated equally throughout our lives. We've never fully lived up to that idea, but we've never walked away from it either. And i won't walk away from it now. [applause] pamela brown (voiceover): president biden's team was accused of trying to minimize the obvious. Jeff zeleny: he would walk with his aides around him as he would walk to marine one on the south lawn of the white house so he wouldn't be seen simply walking alone. Pamela brown (voiceover): but soon, the state of the union enthusiasm would ebb, as some felt they were seeing biden aging day by day, week by week. And it would only get worse. Joe biden: making sure that we're able to make every single solitary person eligible for what i've been able to do with the covid excuse me with dealing with everything we have to do with look [music playing] pete g. Writes, “my tween wants a new phone. How do i not break the bank? we gotcha, pete. Xfinity mobile was designed to save you money and gives you access to wifi speeds up to a gig. So you get high speeds for low prices. Better than getting low speeds for high prices. Right, bruce? jealous? yeah, look at that. Honestly, someone get a helmet on this guy. Get a free unlimited line for a year when you buy one unlimited line. Plus, get up to $800 off google pixel 9 phones. Switch today! pamela brown: we are hours away from cnn's historic presidential debate. With a stubbornly close election, it could be a make or break moment for both men. Pamela brown (voiceover): a clash of political titans, each campaign filled with vitriol and disdain for their opponent. Donald trump: now, under crooked joe biden, the worst president in the history of our country, the world is in flames. Joe biden: the only loser i see is donald trump. Pamela brown (voiceover): fierce rivals now on a collision course for the white house, facing each other for the first time in four years. David chalian: we were in totally uncharted territory. Subject 4: this was going to be a moment that jolted america awake to this election. This may be the most consequential 90 minutes of their political careers. This might be the most consequential 90 minutes of modern american political history. Anderson cooper (voiceover): we're live from georgia, a key battleground state in the race for the white house. Kate bedingfield: coming into the debate, there was an enormous amount of hype. There was the question of whether trump was going to be able to keep himself in check and not be the kind of most unhinged, deranged version of donald trump. There was the question of whether biden was going to be strong. Was he going to be able to push back on concerns that he was too old to be in the race? pamela brown (voiceover): more than 50 million viewers tuned in to watch the first ever debate between a sitting president and a former president. What they saw was shocking. Joe biden how are you? van jones: from the very moment that biden walked out, my heart just sank into my stomach. He looked like an old lost dude in the park. He did not look like the president of the united states. Pamela brown (voiceover): what they heard was worse. Joe biden: we'd be able to help, make sure that all those things we need to do child care, elder care, making sure that we continue to strengthen our health care system, making sure that we're able to make every single solitary person eligible for what i've been able to do with the covid excuse me, with dealing with everything we have to do with look if we finally beat medicare. Jake tapper: thank you, president biden. President trump? donald trump: he was right. He did beat medicare. He beat it to death. David axelrod: three minutes into the debate, my phone was blowing up from people, some of whom i hadn't heard from for years, just apoplectic. Van jones: the phone started vibrating so much that the desk started vibrating. I've never had that experience before. The text messages started coming in, oh, my god. Oh, my god. This is a disaster. Oh, my god. And people just are like, holy crap. We're watching the end of this campaign. Pamela brown: the debate happens. You're watching it. Bring us into what was going through your mind as you're watching the early minutes of the debate. Seth moulton: i mean, it was really five words. Holy shit, we're going to lose. David chalian: within the first 10 minutes of that debate, this entire presidential election changed. Pamela brown (voiceover): over the course of the next 90 minutes, biden stumbled and often lost his train of thought and missed opportunities to attack his rival. Joe biden: there are 40% fewer people coming across the border legally. That's better than when he left office. And i'm going to continue to move until we get the total ban on the total initiative relative to what we're going to do with more border patrol and more asylum officers. Jake tapper: president trump. Donald trump: i really don't know what he said at the end of that sentence. I don't think he knows what he said either. He's not equipped to be president. You know it and i know it. It's ridiculous. Pamela brown: before the debate, when did you sense like he's not going to be able to do this? jim clyburn: i don't know. I don't know when it was. I know i just sensed something. It's something i got from my mother. I have no idea what it is, but it's something my mother had. She always knew when i was about to get in trouble. Pamela brown: did you cry? jim clyburn: yeah. Pamela brown: watching the debate? jim clyburn: yeah. Anderson cooper: before the debate had even concluded, the white house puts out information that the president is suffering from a cold. Jeff zeleny: i remember getting text messages on my phone from very highranking democrats saying that he's going to have to be replaced. This is a crisis. Anderson, this was a gamechanging debate in the sense that right now as we speak, there is a deep, a wide, and a very aggressive panic in the democratic party. It involves party strategists. It involves elected officials. It involves fundraisers. And they are having conversations about the president's performance, which they think was dismal, which they think will hurt other people down the party in the ticket. And they're having conversations about what they should do about it. Pamela brown (voiceover): the vice president came out and tried to defend the president. Kamala harris: i'm not going to spend all night with you talking about the last 90 minutes when i've been watching the last 3 and 1/2 years of performance. Anderson cooper: can you say that you are not concerned at all, having watched the president's performance tonight? kamala harris: it was a slow start. That's obvious to everyone. I'm not going to debate that point. I'm talking about the choice in november. David axelrod: the fears that people had about age were magnified and sort of hardened by what they saw on the stage. Van jones: i just want to speak from my heart. I love that guy. That's a good man. He loves his country. He's doing the best that he can. Subject 5: if you love the guy, how could you put him out there? if you love him, if you love joe biden if that was my father, you don't put a guy in that situation. David urban: he looked lost. He looked puzzled. He looked bewildered. I just looked at it as that was my father if that was your dad or somebody you loved your grandfather, would you put him in that situation knowing that that might happen, would you put him in that situation? i think not. Pamela brown (voiceover): in the aftermath, biden's team launched into damage control. Joe biden: folks, i don't walk as easy as i used to. I don't speak as smoothly as i used to. I don't debate as well as i used to. Well, i know what i do know. I don't know how to tell the truth. David chalian: he was jetlagged after traveling to europe twice. He flew all the way back to los angeles for a fundraiser, being sick with a cold. Whatever. Joe biden tried day in and day out, none of it stopped the steady drumbeat of calls for joe biden to be replaced at the top of the democratic ticket. Nancy pelosi: i think it's a legitimate question to say, is this an episode or is this a condition? anderson cooper: to your fellow democrats who are continuing to say, look, this was one bad night, you say what? llyod doggett: well, i say that we needed a great night. We got a great disappointment instead. And i think we would be better off if we had a new candidate who could present a new vision for our country. Van jones: the party immediately split into two camps. There was nobody in the middle. You were either in the camp that said you'd be an idiot to replace joe biden. He's won before. There's nobody to replace him. Or people on my side were like the emperor has no clothes. You can't run somebody who can't serve. Jeff zeleny: donors were in a state of panic. They canceled fundraisers. Grass roots donations was not happening. They had built this massive apparatus in battleground states, hundreds of offices. They'd spent tens of millions of dollars on television ads. Joe biden: we had the strongest economy in the world. Jeff zeleny: that money was drying up. Pamela brown (voiceover): biden remained defiant. His team decided that a high stakes, high profile television interview with abc's george stephanopoulos: the week after the debate would prove biden was still the best candidate to take down trump. They were wrong. Joe biden: it was a bad episode, no indicator of any serious condition. I was exhausted. I didn't listen to my instincts in terms of preparing. And i had a bad night. George stephanopoulos: and did you ever watch the debate afterwards? joe biden: i don't think i did, no. David chalian: when he sat down for that george stephanopoulos interview, the stakes could not have been higher for him. He needed a home run of a public appearance here. And he did anything but that in this interview. It wasn't a catastrophe like his debate performance was. But that moment when he couldn't even remember if he had actually watched the debate confounded many people looking for clues that he has what it takes to remain in this fight. Seth moulton: i think in some ways he made it worse, because he almost sounded a little arrogant and obstinate. Jeff zeleny: that was supposed to be the moment to turn the corner. And it didn't at all because it showed just how dug in president biden was. He said it would take the lord almighty to get him out of this race. Joe biden: and i'm not done. Pamela brown (voiceover): coming up, as the pressure mounts to end his reelection bid, the president digs in deeper. Joe biden (voiceover): the bottom line here is that we're not going anywhere. I am not going anywhere. [music playing] pamela brown: it has been a week and the fallout continues because we're just getting news that congressman moulton, the democrat, is officially now calling for biden to step aside. Bring us into what you were grappling with and how you finally decided to go public and call on him to step aside. Seth moulton: one of the first things i did is i invited a bunch of local democrats who i represent to just share their views. Probably about 80% of the democrats who spoke thought he should get out of the race. And after hearing that, i said it's not enough for me to sit here in silence. Pamela brown (voiceover): early calls from democrats for biden to step aside didn't seem to make a difference. Joe biden (voiceover): the bottom line here is that we're not going anywhere. I am not going anywhere. I wouldn't be running if i didn't absolutely believe that i am the best candidate to beat donald trump in 2024. Pamela brown (voiceover): he sent a letter to congressional democrats stating he was, quote, firmly committed to staying in this race. Katie rogers: joe biden is somebody who has been defiant and happy to run against the odds for his entire career. It's part of his personality to be the comeback kid, even though he's 81 years old. Pamela brown (voiceover): biden rallied support from members of the congressional black caucus who vowed to stand by his side. Did you think it was inevitable at some point that he would probably step aside? jim clyburn: at first, no, i didn't think it was inevitable because i saw what the public reaction to it was. And i was talking to people, voters were not holding this against him. I said, they are still with him. And i think they are locked in. Pamela brown: and when you were standing by him, you didn't feel like you were putting man over country? jim clyburn: no. I mean, he's going to put the country first no matter what. And that's what was happening. Pamela brown (voiceover): biden kept a small circle of advisors and relied heavily on his family for support. David chalian: they were standing in total solidarity with him. And so joe biden spent weeks in a posture of not even listening seriously to the criticism, to the concern, to the panic that was quite apparent in his party. Pamela brown (voiceover): then reports surfaced that a parkinson's disease specialist visited the white house at least eight times in the past year. Jeff zeleny: it opened the door to a series of questions. And whether or not this doctor was seeing the president every time, it actually didn't matter. It turned out he did not. This doctor did examine the president during his physical, but it just kept the questions alive. Pamela brown (voiceover): calls grew louder for the president to undergo cognitive testing. Sanjay gupta: anyone over the age of 65, again, should be getting this sort of testing. Pamela brown (voiceover): including from our own chief medical correspondent, dr. Sanjay gupta, who wrote an essay advocating for biden to get tested after his june debate performance raised concerns about his mental and physical acuity. Sanjay gupta: there was cause for concern, stumbling of speech, sort of confused, rambling at times, and then also motor symptoms, lack of expression in the face. None of those things are diagnostic of anything. I just want to be clear about that. But in aggregate, they are flags. Pamela brown (voiceover): after his halting debate performance, biden dropped in the polls. Harry enten: joe biden trailed going into that debate by maybe a point or so nationally. We saw that trump extended his advantage nationwide to about three or four points. And more than that, you saw him extend his advantage in some of the key battleground states. David axelrod: and so in a debate that everyone hoped would lift him and get him back into the race in a big way had the opposite effect. Pamela brown (voiceover): but biden was seemingly undeterred. Mj lee: the campaign strategy and the fallout of the debate was to just get the president out there more. But the problem was that his performance was really quite mixed. Pamela brown (voiceover): like this interview with lester holt. Lester holt: who do you listen to on deeply personal issues like the decisions whether to stay in the race or not? joe biden: me. Pamela brown (voiceover): at a solo news conference, biden called vice president kamala harris, vice president trump. Joe biden: look, i wouldn't have picked vice president trump to be vice president, did i think she was not qualified to be president. Van jones: if biden got through an interview or through a press conference, 99% perfect, the 1% mistake was only by i want to talk about. Pamela brown (voiceover): like calling ukrainian president volodymyr zelenskyy, president putin. Joe biden: ladies and gentlemen, president putin. President putin. You can beat president putin, president zelenskyy. Van jones: you can't win the presidency when people are tuning in just to watch and see if you make a mistake. It's literally just people munching popcorn, waiting for the mistake, waiting for the gaffe. Pamela brown (voiceover): actor george clooney, who headlined a major fundraising event for biden weeks earlier, wrote an op ed in the new york times, calling on the president to step aside from the race. David axelrod: so you're faced with a situation where your money is shrinking, the battleground is growing, and your numbers are bad. The writing was very much on the wall. Mj lee: privately, nancy pelosi and barack obama were quite concerned. And they were worried that it was becoming increasingly more difficult for president biden to defeat donald trump. Pamela brown (voiceover): senate majority leader chuck schumer met with biden in delaware on july 13. Jeff zeleny: it was that conversation with senator schumer that was really leading people to believe that president biden would actually see the light and follow all of these pleas for him to get out of the race. Pamela brown (voiceover): that same day, there was an assassination attempt on donald trump in butler, pennsylvania. Donald trump: if you want to really see something that's sad, take a look at what happened van jones: and all of a sudden, i started getting text messages. Oh, my god. Oh, my god, are you seeing this? and someone has sent me the picture of donald trump standing up with his fist in the air and the american flag behind him. I said, this is over. Because it was such a perfect encapsulation of the strength of the trump campaign and trump as a candidate versus the fragility of our candidate. David chalian: it served an immediate political purpose of unifying republicans around donald trump. You saw a surge in his grassroots online fundraising. And he's now entering into his convention as a hero. Jeff zeleny: all the work that democrats had done was essentially a race that weekend. The assassination attempt really encouraged and led president biden to double down on staying in the race. Pamela brown (voiceover): but his respite didn't last long. In the end, more than three dozen democrats publicly called for biden to exit the race. Pamela brown: two days before he steps aside, you write this op ed. It's an op ed where you also say you believe he potentially didn't recognize you in a small circle. Seth moulton: every time i've seen the president, or the vice president before that, he's so excited to see me. I mean, immediately he would pick me out of a crowd, even of colleagues. He just never seemed to never seem to recognize me. Pamela brown (voiceover): days before dropping out of the race, the president tested positive for covid. Images showed him looking frail as he exited air force one to isolate at his beach house in delaware. Jeff zeleny: it was almost tragic in the way that this unfolded in a shakespearean way. Franklin foer: the walls are closing in on him. People that he admires and has worked with forever are telling him, joe, it's time to step aside. Jeff zeleny: and we're told president biden was furious at nancy pelosi. He was furious that president obama didn't have his back. But it still wasn't until really the final day, that's when he really came to believe that he could not win. Subject 6: this is a completely lonely, sad moment for this guy who is the ultimate politician, who feels totally at ease and at home in the oval office, and it's being ripped away from him. Jim clyburn: i was disappointed but not surprised, because i spent two days with him the previous week. And i could feel it. And i could see it. The fire was not in the belly that you need to have to run a campaign like this. Van jones: and then ping, he's out. No warning. No leak. Nothing. Just literally, it's sunday. Everybody's hanging out with their kids. And the biggest news of the decade lands in your cell phone. Pamela brown (voiceover): the news came in a letter posted to social media. David axelrod: i reacted in a way i never really expected, but i teared up because of the magnitude of the decision and because i knew how hard that must have been for a guy who has done so much for the country. Van jones: joe biden's body may not be as strong as it used to be. His language skills may not be as sharp as it used to be. His heart is as big as ever. His heart is as big and as true and as strong. And this is the difference between a politician and a leader. We love the guy. We do. And i wanted to share that. I figured he's probably watching to see how it's going out, shaking out. And i felt like i was talking to him. I wasn't talking to the cnn audience. I was talking to my old boss. Pamela brown (voiceover): coming up, president biden speaks to the country for the first time since stepping away from the campaign. Joe biden: it's been the honor of my life to serve as your president. Pamela brown (voiceover): and he endorses vice president harris, who quickly becomes the presumptive democratic nominee. Kamala harris: do we believe in the promise of america? crowd: yes. Kamala harris: and are we ready to fight for it? anderson cooper: right now, we are about to go to the oval office and hear this historic address from president biden. Joe biden: my fellow americans, it's been the honor of my life to serve as your president. But nothing, nothing can come in the way of saving our democracy. Pamela brown: how would you describe president biden's legacy? seth moulton: he'll go down in history as a great american leader. But the amazing part is he might be remembered best for that big decision he made. Van jones: joe biden will be remembered as an american hero, as a man of character. And when it was time to go, he handed the keys over to a new generation. When the country needs you, you step up. And when it's time, you step back. That's leadership. Jeff zeleny: vice president harris found out on sunday shortly before the announcement that biden was stepping aside, and she knew that he would endorse her. Kate bedingfield: he has enormous trust in her and sees her as part of the future of the democratic party. Jeff zeleny: he believed it was the best way for the party to move on. Joe biden: i'm watching you, kid. Kamala harris: it is my intention to go out and earn this nomination and to win. Franklin foer: in his heart of hearts, did he think that she was the best candidate for president? i'm not sure. But the alternative was the unknown. Jeff zeleny: so an act of loyalty, no doubt endorsing harris, but also an act of practicality and pragmatism. Kaitlan collins: president biden's decision to drop out and pass the torch to his vice president kamala harris is an earthquake of historic proportions. More than $100 million since announcing her presidential campaign just on sunday. Nearly 30,000 volunteer signups, which is 100 times the average daily. David chalian: and while the party has been wary of the word coronation, boy, they got something very close to a coronation with how quickly the party coalesced around harris. Anderson cooper: lightning speed, vice president harris tonight securing enough delegates to win the democratic nomination for president. Mj lee: there was so much speculation before the president made his decision to drop out about, would there be an open convention? joe manchin: a lot of people would like to see a mini primary. David axelrod: there are a lot of folks, and i was one of them who thought she might be strengthened by a competition. Jeff zeleny: but all the talk about an open convention that quickly closed when president biden announced his support for kamala harris. Jim clyburn: everybody knows what happened in 1968. [video playback] we wouldn't have to have gestapo tactics in the streets of chicago. [end playback] kate bedingfield: the democratic party was completely exhausted. They didn't want any more political chaos. David axelrod: and the speed in which that happened is owed, at least, to the threat of donald trump, which democrats feel so intently. Pamela brown (voiceover): meanwhile, trump and his campaign quickly pivoted to attacking harris. Donald trump: kamala, you've done a terrible job. You've been terrible at everything you've done. You're ultra liberal that we don't want you here. We don't want you anywhere. Kamala, you're fired. Get out of here. You're fired. Katie harris: the trump campaign had been planning for a harris candidacy. It just was a matter of when that would happen. [audio playback] i am kamala harris. My pronouns are she and her. [end playback] pamela brown (voiceover): she covered up joe's obvious mental decline. Donald trump (voice over): she wants open borders. She wants things that nobody wants. David urban: at the end of the day, kamala harris is wedded to the biden record. She's just as responsible for the failed border policies, for the failed crime, for immigration, for the debacle in afghanistan, for our foreign policy failures. Jd vance: the biden record is the kamala harris record. Anderson cooper: you've got 100 days figuring out how to define kamala harris. To the american public is now a challenge for both the trump campaign and a potential opportunity for the biden campaign. Van jones: one way or the other, the course of american democracy is going to be determined by this matchup. Pamela brown: this momentum around her, and you have to wonder how that makes joe biden feel. Mark ein: i really believe that at the end of the day, he wants what's best for this country. And the fact that she's getting off to a great start is something that makes him really, really happy. Jim clyburn: i think he'll be the happiest guy in the world to see her sworn in. Pamela brown: what if she loses? jim clyburn: it won't be on him. It would be on us. Evan osnos: if she loses in november, i think, part of biden's legacy will be entwined with that agonizing period. Could he have left earlier, maybe he should have forged ahead, but i don't think it will ever completely console the fact that he had to pull up short of the goal that he had been aiming for. Joe biden: i made my choice. Now the choice is up to you, the american people. God bless you all. And may god protect our troops. [music playing]