The high stakes this year were underlined by the election speeches at the Biden event in New York last, brining record amounts of cash into Biden's campaign coffers. Via BBCnews.com:
Senate Majority Leader and New York Senator Chuck Schumer told the raucous crowd of 5,000 Democrats they must do whatever they could to ensure that the "dishonest, chaotic, ineffective regime of Donald Trump" did not return.
Comedian Mindy Kaling hosted the event and spoke just moments after singer Lizzo finished a rendition of her hit About Damn Time. Other stars such as Queen Latifah and Cynthia Erivo also took the stage.
But the longest standing ovation was saved for the moment when the three presidents - Mr Biden, Mr Obama and Mr Clinton - came out.
Chants of "four more years" echoed throughout the auditorium for Mr Biden.
"Three presidents... and none of them are here [in New York] to go to court," joked comedian Stephen Colbert, alluding to Mr Trump's legal troubles.