Senator JD Vance of Ohio has been dogged by questions over whether he accepts that his running mate, former President Donald J. Trump, lost the 2020 election. But on Wednesday at a rally in Pennsylvania, he gave a crowd of supporters a clear answer: “No.”

Mr. Vance, speaking before a crowd in Williamsport, Pa., was pressed about his reluctance to acknowledge Mr. Trump’s 2020 loss by a reporter, who asked: “What message do you think it sends to independent voters when you do not directly answer the question, did Donald Trump lose in 2020?”

“I’ve answered this question directly a million times,” Mr. Vance responded. “No. I think there are serious problems in 2020. So did Donald Trump lose the election? Not by the words that I would use.”

Mr. Vance, a former Trump critic who once said he was a “never Trump guy,” said after the 2020 race that the election had been stolen from Mr. Trump. When asked about those comments during a Senate campaign debate in 2022, Mr. Vance stood by his remarks. “Yeah, look, I have said that, and I won’t run away from it,” Mr. Vance had said.

At the time, he pointed to state court rulings concerning elements of how Pennsylvania had conducted its election, even though none of those rulings called the results into question.

But he stumbled during the vice-presidential debate on Oct. 1 when questioned about Mr. Trump’s claims that he won in 2020, trying to pivot to claims about censorship. And when Gov. Tim Walz of Minnesota, Vice President Kamala Harris’s running mate, asked point-blank whether Mr. Trump lost, Mr. Vance avoided the question entirely.

“Tim, I’m focused on the future,” Mr. Vance said. Mr. Walz called it a “damning non-answer.”

Since then, Mr. Vance has appeared frustrated by repeated queries about 2020, including in an interview with The New York Times published last week, when he evaded the question five times.

During that interview, Mr. Vance suggested Mr. Trump would have won more votes in 2020 had social media companies not limited posts about a New York Post story about the contents of a laptop that belonged to Hunter Biden, President Biden’s son. Trump allies had maintained that documents on the laptop linked President Biden to corrupt business dealings, but those claims were unfounded.

Mr. Vance repeated those claims on Wednesday.

“What verifiably I know happened,” Mr. Vance said, “is that in 2020, large technology companies censored Americans from talking about things like the Hunter Biden laptop.”