For much of Wednesday evening, Gavin Newsom, the Democratic governor of California, drew nearly as much attention at the Ronald Reagan Presidential Library and Museum in Simi Valley, Calif., as the Republican presidential candidates who were there for their second debate.
Mr. Newsom spoke to Fox News, MSNBC and CNN. He was there before the debate, shuttling from microphone to open notebook, and stayed long after the Republican candidates headed out, thronged by reporters as he talked down the Republican field and talked up President Biden.
“Clearly Joe Biden walks away with this debate,” Mr. Newsom said to a jostling crowd who sought his reaction afterward. “And maybe Donald Trump. It’s just the J.V. team. These guys are maybe running for vice president.”
Mr. Newsom went to Simi Valley, aides said, at the request of the Biden campaign, which — in what has long been standard practice — assigns high-profile surrogates to talk to reporters and television correspondents at moments like this.
But Mr. Newsom was no ordinary surrogate. A bundle of energy and sharp-edged quotes who seems to relish the prospect of scrapping with high-profile conservative hosts like Sean Hannity, Mr. Newsom left little doubt that he has become the leading surrogate for not only Mr. Biden but also for himself, as he considers a run for the White House in 2028. (He’s also waiting by the sidelines on the off chance that Mr. Biden ends up not running in 2024.)
“What Gavin fundamentally gets is that Democrats want leaders who speak with confidence about the future with an intergenerational credibility, can take a punch but hit back harder and don’t begin their sentences with talking about House resolutions or Senate bills or various acronyms,” said Chris Lehane, a Democratic consultant who has worked in national and California politics. “He goes on these shows playing to win, not as if they are a Harvard-Yale debate.”
Mr. Newsom is not the only Democrat with a political future who has been out making the case for Mr. Biden. He is part of a next-generation field that includes, among others, three governors: Gretchen Whitmer of Michigan, Josh Shapiro of Pennsylvania and J.B. Pritzker of Illinois. But none have been quite as active in this slow roll-up to the Iowa caucuses as Mr. Newsom, who has been traveling across the country.
“I think this is in equal service to Biden ’24 and Newsom ’28,” said Matt Bennett, a founder of Third Way, a centrist Democratic organization. “He’s clearly genuine in his support for the president, and he is obvious in his intent to run someday.”
And Mr. Newsom is now set to debate Gov. Ron DeSantis, the Florida Republican seeking his party’s presidential nomination, in Georgia this November. That unusual face-off — between two sitting governors, one of them a presidential candidate — came up often as Mr. Newsom boasted that he had baited Mr. DeSantis into this encounter.
“Why is he doing it?” Mr. Newsom said on CNN. “The fact that he took this debate, the fact that he took the bait in relation to this debate, shows he’s completely unqualified to be president of the United States. Why is he debating a guy who’s not even running for president when he’s running for president?”
Mr. Newsom made much the same point at another of his round-robin, post-debate sessions, this one with Mr. Hannity of Fox News, which will host the DeSantis-Newsom skirmish. Mr. Newsom laughed when Mr. Hannity suggested that his real agenda was positioning himself to be the Democratic candidate for president.
“Joe Biden’s our president,” Mr. Newsom said. “Joe Biden is going to win this election.”