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