Biden Stumbles Over His Words as He Tries to Steady Re-Election Campaign

President Biden sought to steady his re-election campaign by talking with two Black radio hosts for interviews broadcast on Thursday, but he spoke haltingly at points during one interview and struggled to find the right phrase in the other, saying that he was proud to have been “the first Black woman to serve with a Black president.”

He also stumbled over his words during a four-minute Fourth of July speech to military families at the White House, beginning a story about former President Donald J. Trump, calling him “one of our colleagues, the former president” and then adding, “probably shouldn’t say, at any rate” before abruptly ending the story and moving on.

Mr. Biden made the mistake on WURD radio, based in Philadelphia, as he tried to deliver a line that he has repeated before about having pride in serving as vice president for President Barack Obama. Earlier in the interview, he boasted about appointing the first Black woman to the Supreme Court and picking the first Black woman to be vice president.

The president also made a mistake earlier in the interview when he asserted that he had been the first president elected statewide in Delaware. He appeared to mean that he was the first Catholic in the state to be elected statewide, going on to speak admirably of John F. Kennedy, a Catholic.

Mr. Biden and his top aides have said the president’s activities in the coming days are part of a series of campaign efforts designed to prove to voters, donors and activists that the president’s debate debacle was nothing more than what he has called “a bad night.”

All of the president’s appearances have come under intense scrutiny since he appeared listless and distracted in the debate against former President Donald J. Trump last Thursday, a performance that triggered a wave of anxiety among Democrats about whether he is too old to remain as the party’s nominee.

The president is scheduled to sit down on Friday for an interview with ABC’s George Stephanopoulos after a campaign rally in Madison, Wis. On Sunday, he is scheduled to appear at a campaign event in Philadelphia.

On Thursday, the president used the radio interviews to try to dispel concerns about the debate among members of the Black community.

In Mr. Biden’s appearance on the “The Earl Ingram Show,” which is aimed at Black listeners in Wisconsin but is also broadcast around the country, Mr. Ingram opened his show by asking the president to “speak to some accomplishments that we may or may not be familiar with about your record.”

But despite the low-pressure nature of the interview, the president at times spoke haltingly as he delivered his rapid-fire answers. Asked why voting mattered, Mr. Biden gave an answer about the Supreme Court’s ruling this week on immunity for Mr. Trump.

“You need someone, someone who is going to make sure that — the Supreme Court just issued a decision, by the way, that threatens the American principle that we have no kings in America,” he said. “There’s no one above the law.”

“That’s where we always — we gave Donald Trump executive — a power to to use a system — and it’s just never contemplated by our founders because of the people he appointed to the court,” he said, appearing to stutter several times, a condition he has struggled with since he was a child. “It’s just presidential immunity. He can say that I did this in my capacity as an executive, it may have been wrong, but I did it. But that’s going to hold — because I — and this is the same guy who says that he wants to enact revenge.”

The president’s responses to Mr. Ingram’s four questions were lengthy as he largely stuck to listing his accomplishments in office and criticizing Mr. Trump. But in the 17-minute interview, he sometimes stopped himself in the middle of an answer.

In the answer about the importance of voting, he began talking about Mr. Trump’s proposal to increase tariffs on all Chinese goods imported into the United States. He cut himself off in the middle of the answer, apologizing for going on too long.

“He wants a 10 percent tariff on everything imported to the United States,” he said, “which experts point out is going to raise the taxes on average Americans 2,500 bucks, raise the taxes while he gives a $5 trillion tax cut next time out for everybody making — anyway, just, I don’t want to get too wrapped up in it, really.”

Mr. Biden also stopped himself from using an epithet to describe Mr. Trump during an answer in which he talked about his son Beau, who died from brain cancer after serving for a year in Iraq. Mr. Biden has placed the blame for his death on his proximity to so-called burn pits, where waste was disposed of.

“He went a very healthy man, came back with Stage 4 glioblastoma — more brain injuries in that war than any other war — and he died,” Mr. Biden said. “I’ll be damned if I let this S.O. — excuse me — this president, talk about veterans the way he talked.”

At the end of the interview with Mr. Ingram, the president once again acknowledged his poor debate performance.

“The fact of the matter is that, you know, it was — I screwed up,” he said. “I made a mistake.”