[Source: Reuters]

President Joe Biden faces close scrutiny in public appearances on Thursday and over the U.S. holiday weekend, as he resists pressure to end his reelection bid after a poor debate performance raised concerns about his stamina and mental acuity.

The 81-year-old Democrat’s shaky showing at a June 27 debate with Republican rival Donald Trump has sparked questions about his ability to keep up a grueling pace of work for the next 4-1/2 years and calls from some in his party to step aside.

Vice President Kamala Harris is the leading contender to take his place in the Nov. 5 election if Biden were to drop out, sources have said, though his allies believe he can assuage the concerns of voters and donors.

Biden will host the annual July 4 Independence Day festivities at the White House on Thursday, give an interview to ABC News on Friday that will be aired in full at 8 p.m. ET (0000 GMT Saturday) and travel to Wisconsin the same day for a campaign rally.

Dozens of Democrats in the House of Representatives are watching closely and prepared to ask Biden to step aside if he falters in the ABC interview, a source told Reuters.

Democrats see capturing control of the House in November as critical, as it could be their last hold on power in Washington if Trump returns to the White House and Republicans capture the Senate.

Biden faces a new reality since last week’s debate – even if he doesn’t falter verbally or physically, serious concerns about his viability as a candidate are likely to linger.

If he does mangle words or look unfocused or confused, he will face renewed pressure to depart.

If reelected, Biden would be 86 at the end of a second term. He is being asked by some former supporters to step aside to preserve his legacy and lessen the chances of a second Trump presidency.

With just four months to go before the election, a decision needs to be made soon, they say.

Democrats, including top allies, have left the door open to having Harris at the top of the Democratic ticket.