Biden is holding a rare solo news conference to try to show he’s up for this campaign

President Biden faces yet another high-profile public test of whether he’s sharp enough to campaign for a second term when he takes questions from reporters on Thursday.

It comes as Biden wraps up a summit of NATO leaders in Washington, D.C., an event his campaign had hoped would showcase his leadership on the world stage. Instead, it has been overshadowed by doubts about whether he is up for a bruising campaign and another four years in office — doubts expressed by elected Democrats, donors and voters.

The questions have been swirling since Biden badly fumbled his June 27 debate against former President Donald Trump. Biden struggled to answer questions in that debate and has since blamed it on a cold, latent jet lag, overpreparation and interruptions from Trump. He said it was just one bad night, but many in his party aren’t convinced.

Watch Biden's press conference, slated for 6:30 p.m. Thursday, here:

Since then, Biden and his team have worked to prove he does have the stamina and mental acuity to run this race, adding campaign stops in Wisconsin, Pennsylvania and later this week in Michigan. He did a television interview that aired in full on ABC News and has another one scheduled on Monday with NBC, and he called in to MSNBC’s Morning Joe this week, too.

Biden told his party to stop talking about whether he should quit because he's staying in

Biden has turned defiant, telling his party that he’s staying in the race and it was time to stop talking about whether he should quit. He has received wholehearted support from some important figures in the party — but others have since come out and said they think he will lose to Trump.

Most recently, actor George Clooney, who just hosted a blockbuster fundraiser for Biden