Most recently, the debate between President Biden and Trump changed the course of the 2024 campaign after Biden's poor performance exacerbated Democratic and voter concerns about his age and fitness to serve another four years. He announced he was exiting the race 24 days later.

Former President Donald Trump and Vice President Kamala Harris go head to head in tonight's debate hosted in Philadelphia by ABC News.

The event will offer Americans their most detailed look at a campaign that’s dramatically changed since the last debate in June.