Biden Campaigns in Pennsylvania, as Calls Continue for Him to Quit the Race

President Biden will continue his efforts to rescue his imperiled re-election effort on Sunday, with two campaign stops in Pennsylvania, a key swing state.

Mr. Biden will visit Philadelphia and then Harrisburg, as a growing number of Democrats from across the party’s ideological spectrum are calling for him to drop out of the race over concerns about his age and mental sharpness.

Pennsylvania is one of the states that Mr. Biden almost certainly must win if he hopes to retain the White House. And its largest city, Philadelphia, is one of his favorite places to campaign. But former President Donald J. Trump has pulled ahead in the state in many polls.

Mr. Biden won Pennsylvania in 2020, but Mr. Trump now leads the president by about three percentage points, according to a FiveThirtyEight polling average. Gov. Gavin Newsom of California, a top Biden surrogate, spent Friday and Saturday campaigning for the president in Western Pennsylvania and Bucks County, a hotly contested battleground.

Mr. Biden had been expected to speak at a meeting of the National Education Association in Philadelphia on Sunday, but he pulled out after the powerful education union’s staff went on strike. He will instead deliver an address at a church service in Northwest Philadelphia on Sunday morning.

“President Biden is a fierce supporter of unions, and he won’t cross a picket line,” Lauren Hitt, a Biden campaign spokeswoman, said in a statement.

After Philadelphia, Mr. Biden will travel to Harrisburg for a community organizing event with union members on Sunday afternoon. His campaign said he would be joined throughout the day by Gov. Josh Shapiro and Pennsylvania’s two senators, Bob Casey and John Fetterman, both Democrats.

Since a poor debate performance where he frequently lost his train of thought, Mr. Biden has largely stuck to delivering prepared remarks from a teleprompter. Without the device, he has sometimes struggled to speak clearly.

This week, he stumbled over his words during two radio interviews, even though his aides had provided the hosts with the questions, a practice that goes against standard journalistic ethics. And he gave several confusing answers during an interview with ABC News on Friday.

Even Mr. Biden’s allies have said that his campaign should ensure that he appears more in public without a teleprompter to demonstrate his mental sharpness.

“They don’t need scripted remarks,” said Steve Sisolak, the former Democratic governor of Nevada, who supports Mr. Biden. “He needs to show people that he can do it on the spot and answer questions — tough questions — and be out there with voters. Be out there, mingle with your folks.”

Despite doubts from many Democrats, Mr. Biden has defiantly insisted that he will stay in the race. On Friday, the president told ABC News that only the “Lord Almighty” could force him to drop out.