HUDSON, New Hampshire — In a free-wheeling town hall-style event, Joe Biden dropped most of his attacks on his 2020 Democratic rivals and instead fended off several frustrated voters.

At a presidential campaign stop in Hudson, New Hampshire, Biden, 77, held court for about 90 minutes, an unusual amount of time for his second question-and-answer format of the day.

Two voters grilled him on his potential vice presidential pick, a question all the Democratic White House candidates have fielded.

Although Biden was reticent to name a running mate for fear of appearing presumptuous, he said he understood the importance of the question in case "lightning strikes," and he dies in office.

He promised that he would choose someone younger than him, who was still job ready for Day One as long as there was a "correlation" between their beliefs, such as his position against Bernie Sanders's version of "Medicare for all."

Biden, himself a former vice president, hinted he would consider former mayor of South Bend, Indiana, Pete Buttigieg, despite spending all of Saturday mocking his inexperience, including in a negative digital ad, a rally, and a press conference.

"There are at least four people running that are, in fact, in simpatico with where I am, starting with Indiana," he said on Sunday. "And don't read that as ... I'm getting in trouble here."

Biden's attacks on Buttigieg were interpreted as a campaign strategy change after a disappointing fourth-place finish in Iowa.

The 36-year Delaware senator tamped down the rhetoric a day later, instead focusing on the struggles of working-class people and responding to voter concerns at his events, another tactic mix-up.

But he's running out of time to make an impact ahead of New Hampshire's primary on Feb. 11, though he's already tried to manage expectations for the second contest. Rather, he's relying on strong performances in Nevada and South Carolina, more diverse early voting states.