PHILADELPHIA — President Biden attended a Black church and was rallying with union members on Sunday in the critical swing state of Pennsylvania, trying to project enough strength for his reelection campaign to quell a growing clamor from within in his own party for him to bow out of the race.

The appearances followed Biden joining a Saturday call with campaign surrogates, and reiterated that he has no plans to step aside, while urging unity among top Democrats. But he also listened to concerns and feedback, according to two people who spoke on condition of anonymity to discuss private conversations.

The president pledged on the call to campaign harder going forward and to hit the road more frequently, taking his message to voters more directly. He got the chance at a church service at Mount Airy Church of God in Christ in northwest Philadelphia, where Biden entered the gold-chandeliered sanctuary to applause and a cry of “Let him know we are with him!” which drew a “Hallelujah!” from one parishioner says.

Early in the service, Pastor Louis Felton asked churchgoers to lock arms before declaring, “There is no election we can not win.”

“There is no enemy we can not defeat,” Felton said. “We are together because we love our president.”

The president was later heading to Harrisburg to speak at an organizing event with union members and local Democrats. On Sunday evening, he returns to Washington, where leaders from NATO countries will gather for a three-day summit beginning Tuesday to mark the military alliance’s 75th anniversary.

The focus could shift more to Russia’s war in Ukraine than questions about Biden’s reelection campaign, but the 81-year-old Biden’s political situation remains precarious. Five Democratic lawmakers have called on him to abandon his reelection bid ahead of November, and more could do so in coming days, as Congress reconvenes.

Meeting in person will give congressional Democrats a chance to discuss concerns about Biden’s ability to withstand the remaining four months of the campaign — not to mention four more years in the White House — and true prospects of beating former Republican former President Donald Trump.

Biden’s campaign team is quietly bracing for the chorus of those calling for him to leave the race to grow in coming days — holding the call with surrogates and calling and texting lawmakers to try and head off more potential defections. The president also got a weekend boost from other key Democrats who had raised previous questions but now have moved to support him, led by Speaker Emerita Nancy Pelosi and Rep. James Clyburn of South Carolina.

With the Democratic convention fast approaching, the short term is especially critical.

What to know about the calls for President Biden to drop out of the 2024 race:

• President Biden’s poor performance in the first 2024 presidential debate left some Democrats unsure of his fitness for office and future as the party’s candidate.
• More than a dozen congressional Democrats have joined in calling for Biden’s exit from the race. Former Biden supporter George Clooney echoed these calls in an op-ed published in the New York Times just weeks after he helped lead a record-breaking fundraiser for the Democrat.
• Democratic voters have continued to raise concerns about Biden’s nomination since the debate, with speculations and suggestions for replacement nominees running rampant.
• Biden’s former running mate Barack Obama has reportedly been trying to pressure him to drop out, and had prior knowledge of Clooney’s op-ed. Former House Speaker Nancy Pelosi allegedly told Biden he could not beat former President Donald Trump this time around.
• As the Democratic National Convention approaches, California delegates for the Democratic Party are reportedly in disarray as debate over the president’s chances of re-election threatens to tear the party apart.
• However, the Biden campaign has denied any plans for Biden to bow out and for Kamala Harris to step in as the Democratic nominee. Sources close to the president believe he might not be willing to drop out, while other sources claim he is “receptive” to giving up on a second term.

Since his disastrous debate performance late last month donors, strategists, lawmakers and their constituents have urged Democrats to replace him at the top of the ticket before, they argue, it’s too late. Biden’s Friday interview with ABC has not convinced some who remain skeptical that he can resurrect his campaign.

Biden has insisted he’s not yielding to any other potential Democratic presidential candidate, arguing that he’s still the party’s best shot to beat Trump. His visiting a Black church, gives him a chance to energize African-American voters, who are Democrats’ largest and most-loyal bloc of support. It could also send a message to members of the Congressional Black Caucus, whose endorsement the president will need as he works to quell potential rebellion on Capitol Hill.

At the Essence Festival of Culture in New Orleans on Saturday, Biden got enthusiastic support from four of the caucus’ members, including Rep. Joyce Beatty, D-Ohio, who told attendees “don’t get out there and turn your back on this president.”

California Democratic Rep. Maxine Waters, who is 85, drew a standing ovation by declaring, “People say Joe Biden’s too old. Hell, I’m older than Biden!”

“It ain’t gonna be no other Democratic candidate,” Waters said “and we better know it.”

Others aren’t fully convinced.

Democratic Sen. Chris Murphy of Connecticut told CNN said that Biden “needs to answer those questions that voters have” but added, “If he does that this week, I think he will be in a very good position and we can get back to what this campaign needs to be.”

During his Friday interview, Biden rejected undergoing independent cognitive testing, arguing that the everyday rigors of the presidency were proof enough of his mental acuity. But California Democratic Rep. Adam Schiff told NBC on Sunday that he’d be “happy if both the president and Donald Trump took a cognitive test.”

Schiff added that the president opting to stay in the race “is going to come down to what Joe Biden thinks is best” and that he could “run hard” to beat Trump or “if his decision is to pass the torch, then the president should do everything in his power to make that other candidate successful.”

Schiff warned that Biden needs to consider how he risks dragging down Democrats down the ticket: “Look, there are concerns with the impact on down ballot races if the president doesn’t do well.”

“You can only run so far ahead of the president,” he said.

As some Democrats have done, Schiff also seized on Biden suggesting during the ABC interview that losing to Trump would be acceptable “as long as I give it my all.”

“This is not just about whether he gave it the best college try,” Schiff said “but rather whether he made the right decision to run or to pass the torch.”