Struggling Biden faces big test with ABC interview, vows to fight on

President Joe Biden, scrambling to defuse a political crisis over his shaky debate performance, will participate in a television interview on Friday that will be closely watched for signs of whether his mental acuity is failing.

Biden will travel to Madison, Wisconsin, to rally Democratic voters. During the trip he will be interviewed by ABC News, part of a flurry of events over the next week aimed at showing Americans he still has the stamina to run against Republican candidate Donald Trump in the Nov. 5 election.

While Biden insists he is staying in the race and that his health is not faltering, he is under enormous pressure to step aside and open a path for his 59-year-old vice president, Kamala Harris.

Some donors are making their displeasure known loudly, halting funding or looking at possible Democratic alternatives. Even some of Biden's closest political allies, like former Speaker Nancy Pelosi, have raised questions about his health.