U.S. President Joe Biden delivers remarks at a church service at Mt Airy Church of God In Christ in Philadelphia, Pennsylvania, U.S., July.7, 2024. / Reuters/Nathan Howard

HARRISBURG, Pennsylvania (Reuters) -An embattled U.S. President Joe Biden faced escalating pressure from fellow Democrats worried about his candidacy on July.7, concerns he worked to ease with campaign stops in the battleground state of Pennsylvania.

Biden, 81, faces growing calls to end his reelection bid after a halting performance in a June.27 debate with Republican Donald Trump, 78, raised questions about his ability to do the job for another four years. He has vowed to stay in the race, dismissing calls for him to drop out as "nonsense" in a fundraising email on July.6.

On July.7, the Democratic president received a warm welcome at a Black church in Philadelphia and later traveled to the Pennsylvania state capital, Harrisburg, for an event with union members. Black voters are a critical part of Biden's base of support and recent public opinion polling has shown their support for him softening.

On a leadership call on July.7 called by House Democratic Leader Hakeem Jeffries, some House Democrats said that Biden should step aside as presidential candidate, a source familiar with the discussions told Reuters.

Representatives Jerrold Nadler, Adam Smith, Mark Takano and Joe Morelle, senior House Democrats who sit on the Judiciary, Armed Services, Veterans Affairs and House Administration committees, were among those who called on Biden to step aside, according to media reports.

Democrats also suggested that Vice President Kamala Harris, seen as the likeliest candidate to replace Biden in the November.5 election were he to bow out, could perform well.

The coming week is crucial, Democratic Senator Chris Murphy said on CNN's "State of the Union." He encouraged the president to hold a town hall or news conference to convince voters he is "the old Joe Biden."

"The president needs to do more," Murphy said. "I do think the clock is ticking."

Democratic U.S. Representative Adam Schiff said on NBC's "Meet the Press" that Biden needs to move swiftly to put concerns to rest.

He added that he believed Harris "could win overwhelmingly, but before we get into a decision about who else it should be, the president needs to make a decision about whether it's him."

Asked in Harrisburg whether the Democratic Party was behind him, Biden told reporters "yes."

'NEVER COUNT JOSEPH OUT'

In Philadelphia, churchgoers at the Mt Airy Church of God in Christ gave Biden a rousing welcome. Bishop Louis Felton praised him as "a man of vision and integrity."

The bishop, referring to Biden's Republican challenger without naming him, chided those who "make an issue of the president - that he is conditioned with stammering and not being able at certain times to bring forth words - while another person lies fluidly and you never challenge his lies."

"Never count Joseph out," Felton thundered. "Go, Joseph, you can make it."

Biden addressed the congregation for a little more than six minutes, saying, "We must unite America again. That's what I'm going to do."

Carla Greene, a resident of Philadelphia, said she hoped Biden felt the support, adding, "we believe he is the man for the job."

In a July.5 interview with ABC News, Biden said only the "Lord Almighty" could persuade him to drop out, dismissing the prospect that Democratic leaders could join forces to try to talk him into standing down.

A Democratic National Committee member from Florida, Alan Clendenin, joined calls urging Biden to step aside on July.7.

"Joe Biden will be remembered by historians as one of the finest presidents in American history, but this election is about the next four years, not the last three and a half," Clendenin said.

The DNC has steadfastly supported Biden since his debate stumbles so any defections could suggest a deepening of the crisis. DNC Chair Jaime Harrison said on Sunday that Biden remains the party's nominee. "The primary is over," he said.

CRITICAL STATE

Biden stopped at a local campaign headquarters after church, telling supporters there, "Pennsylvania is a critically important state."

Accompanying Biden, Democratic Senator John Fetterman bellowed, "There is only one person in the country that's ever kicked Trump's ass in an election and that is your president."

Biden also met briefly with Pennsylvania's Democratic Governor Josh Shapiro.

Pennsylvania is one of the half dozen or so states alongside Wisconsin and Michigan that can swing Democratic or Republican and are expected to determine the outcome of what has been a tight race.

July.7 trip - Biden's 10th to Pennsylvania during the 2024 election campaign - is part of a July voter outreach blitz by the Democratic Party that includes a $50 million media campaign aimed at events, such as the Olympics, and travel by the president, the first lady, Harris and her husband to multiple battleground states.

Biden will visit swing state Nevada on July.16 and 17, the White House said on Sunday, where he will deliver remarks at the NAACP National Convention and UnidosUS Annual addressing Black and Latino audiences.

Biden will also travel to Austin, Texas on July.15, where he will commemorate the 60th Anniversary of the Civil Rights Act at the LBJ Presidential Library.

Pressure from Congress is expected to ramp up in the coming days as lawmakers return to Washington from a holiday recess and donors mull their willingness to keep funding Biden's campaign.

Biden is also preparing to host dozens of world leaders at a NATO summit in Washington this week and hold a rare solo news conference.

Five U.S. lawmakers have publicly called for Biden to end his reelection bid, including Representative Angie Craig of Minnesota, the first Democratic member of the House of Representatives from a battleground district, with others said to be poised to join in.

Two letters are circulating among House Democrats calling for Biden to step aside, House Democratic sources have said.

Some Democrats have publicly supported Biden's 2024 presidential run.

Senator Bernie Sanders, 82, who has run for the Democratic nomination for president in the past, stood firmly in Biden's camp on Sunday, saying Democrats' focus should be on policy.

"This is not a beauty contest," he said on CBS' "Face the Nation."