For a few minutes Monday afternoon, California Gov. Gavin Newsom was just like any other politician with national ambitions as he weaved his way through a small crowd at a New Hampshire rest stop. He greeted local officials. He touched a baby. He was given a cinnamon-sugar doughnut.
“Everybody’s promoting it,” he said, taking a big bite. “Real life, no bullshit, no politician talking. That’s next level.”
A television microphone burst in. “Governor, should the president step aside?”
Mr. Newsom chewed for a moment, reiterated the next-levelness of the doughnut, and then turned to the microphone. “The answer is no.”
It was back to work for President Biden’s hardest-working surrogate. The half-eaten pastry was passed to a local Biden campaign worker. The doughnut would have to wait.
The stop in New Hampshire was the capstone of a days-long tour of hard-won states on Biden’s behalf, a trip Newsom described Monday in almost evangelical terms: “I have to go out there every day — every day — over and over and over again, to preach the message of his accomplishments, but also of an exciting future.”
In the 12 days since Mr. Biden’s debate performances derailed his re-election bid, cracks of doubt have opened in the party he led four years ago. Democratic leaders, even as they call into cable shows and issue public statements of support for the beleaguered president, appear to be eyeing the exit.
Outside Washington, Mr. Newsom may be Mr. Biden’s most outrageously loyal ally, certainly the only one who spent a long Fourth of July weekend in the rival states of Michigan, Pennsylvania and New Hampshire.
“I decided not to just give up, but to give up,” he said Monday, speaking to reporters herded into an ice cream parlor by Biden campaign staff. “I took my holiday weekend off — it wasn’t easy being away from the kids. I said there was something more important.”
Mr. Newsom, widely seen as having presidential ambitions, has little to lose by backing Mr. Biden as the wealthy, established leader of a powerful, deep-blue state.
He also has a penchant for political combat. He has long been convinced that Democrats are not doing enough to aggressively counter Republicans. He has spent the past year debating Florida Gov. Ron DeSantis and clashing with Fox News hosts, going far from his state to warn voters about the risks of a second Trump administration.
“Gavin Newsom has said he has sub-zero interest in running for president right now,” said Paul Mitchell, a longtime friend of the governor who runs a political data firm in California. “His role is a proxy. He’s a voice for Democrats nationally. That’s exactly what he should be doing.”
Going on the road to support the sitting president is not a risky proposition, Mr. Mitchell said. “I just don’t think there’s a downside.”
When Biden convened Democratic governors at the White House last week to discuss the direction of his campaign, Newsom was the only leader from a state west of Minnesota who attended in person.
After Mr. Biden began the meeting by saying he planned to stay in the presidential race, the first question went to Gov. J.B. Pritzker of Illinois, who asked Mr. Biden how he planned to proceed, according to governors who were present and others briefed on the session.
Mr. Newsom then went to work, offering enthusiastic support for Mr. Biden, telling the president he was the party’s best candidate — an echo of the Biden campaign’s own message, the governors and others familiar with the matter said.
That meeting was practically a job requirement. But New Hampshire, as they say, is a place no one in politics goes by chance, and Mr. Newsom’s mission to defend the president’s record dovetails neatly with his own ambitions.
“Governor Newsom is getting ready for the next phase of his life,” said Lou D’Allesandro, a longtime Democratic senator from New Hampshire. “I’m sure he’s looking at the prize.”
Mr. D’Allesandro said the California governor was also prominent enough to reassure voters about Mr. Biden. For the Biden campaign, he said, “it’s the right move.”
Long before the debate, Mr. Newsom was scheduled to speak Monday night at a fundraising event for Democrats in the New Hampshire Legislature. But as is customary for candidates, mingling at the rest stop outside Manchester kept him busy, as he spoke to supporters and posed for photos while inexplicably clutching an open cup of hot coffee in the stifling heat.
Tim Platt, 65, a school board member from Concord, thanked him for his defense of Mr. Biden. Mr. Newsom said: “He’s supported us for decades, and that’s how I was raised, frankly.”
A few moments later, a man shouted across the food court, “Go back to California, you money grabber!”
Reid J. Epstein, Shawn Hubler And Maggie Haberman contributed to the reporting.
