SAN FRANCISCO — Gavin Newsom didn’t just roll out the welcome mat for Joe Biden when the president landed in San Francisco this week for public events and fundraisers.

During Biden’s three-day swing through the Bay Area, the California governor forcefully embraced his new role: a top Biden surrogate. The trip came days after Newsom took that defense directly into what many Democrats consider the beating heart of enemy territory — over an hourlong interview with Fox News’ Sean Hannity.

The Biden world is taking notice. It wasn’t that long ago when Newsom annoyed Democratic leaders by failing to sufficiently tamp down speculation that he planned to challenge Biden for the 2024 nomination. Then, Newsom frustrated them anew by suggesting they weren’t prepared to take on escalating Republican attacks on issues Democrats hold dear, including abortion rights.

Now, he’s doing the attacking on Biden’s behalf.

Campaigns want surrogates “to be doing both supportive, affirmative messages around the record and agenda. You also want them to take the fight to the other party,” said a Biden adviser of their emerging stable of influential surrogates, speaking freely on the condition of anonymity. On Newsom directly, the adviser said: “Our view is he’s been doing a good job on both.”

While it’s customary for governors to line up behind their party’s president, Newsom has gone to even greater lengths in recent months to demonstrate his fealty and offer up his services to help for 2024.

The California governor hopscotched the Bay Area for nearly 36 hours this week to greet Biden at the airport, speak about the administration’s climate policy at a Palo Alto nature preserve, chat artificial intelligence in San Francisco and co-headline a reelection fundraiser for the president across the Golden Gate in the deep-pocketed woodlands of Marin County.

Appearing before more than 100 donors gathered Tuesday afternoon in Kentfield, Newsom piled on praise, calling Biden a “remarkable leader” who needs another four-year term.

“I am here, Mr. President, as a proud American, as a proud Californian, mesmerized by not just your faith and devotion to this country, and the world we’re trying to build, but by your results, by your action, by your passion, by your capacity to deliver,” he said.

Biden traded compliments with him from behind the microphone at the AI event, calling Newsom his “buddy” and “one of the best governors I’ve ever worked with.”

As the trip wrapped Wednesday, Biden advisers and several aides felt that Newsom and Biden lifted each other up during the visit. And officials back in Washington were commenting to each other about how well things had gone with Newsom, according to people with knowledge of the conversations.

According to aides and close allies, Newsom has coordinated with Biden’s team on everything from his own PAC to national travel to even his major interviews — all with the idea of ensuring he doesn’t fall out of step with the party’s leader. Newsom has long personally maintained a strong relationship with Biden himself, but he previously rubbed some presidential aides and allies the wrong way by calling out the Democratic Party as sluggish in the face of the concerted GOP attacks. Lately, he checks in regularly with Biden’s close-knit circle of top advisers and last year bonded over family and education policy with first lady Jill Biden on a trip to Washington.

“Gov. Newsom loves that man — loves him,” said Anthony York, a Newsom senior adviser.

Newsom sees a role for himself in elevating Biden’s sweeping policy wins, such as the infrastructure, veterans’ health care and computer chips legislation.

“He has a deep respect for him and really does believe that the things he has accomplished — from the IRA to the [infrastructure bill] — are transformational pieces of legislation that will reshape our country for the next 50 years,” York said.

The Biden world, in turn, has come to view the swaggering 55-year-old as an important ally, a younger official comfortable in the ways of modern verbal combat and unafraid to go on offense against the president’s biggest detractors. Pointing to Newsom’s haymakers at former President Donald Trump and Florida Gov. Ron DeSantis, the leading Republican candidates for 2024, the Biden adviser added: “That is being a good surrogate. And appreciated.”

Rep. Anna Eshoo (D-Calif.), who appeared at events this week with Biden and Newsom, said dealing with California’s recent spate of disasters, including historic drought and wildfires, helped the pair forge a tighter relationship. “Steel comes through a great deal of stress,” she said.

Rep. Anna Eshoo (right) said dealing with California’s recent spate of disasters helped the pair forge a tighter relationship.