president who can do that. who can gather up those pieces and bring the american people together. reporter: while others present themselves as fighters. when i got into the race for president, i know what i d be fighting for. i knew who i d be fighting for. reporter: with just 52 days to go before voting starts, candidates are in a fierce debate about what america will need in a post-trump world. what we need to do right now is galvanize, not polarize. butt jeej takiigieg taking a elizabeth warren. we will fight when we must fit but i will never allow us to get so wrapped up in the fighting that we start to think fighting is the point. reporter: biden echoing that message, criticizing the progressive candidate s approach on healthcare. these guys are saying, no, no, my way or the highway. warren hit back in a major speech in new hampshire. and without naming them, targeted biden. unlike some dem some