The day that launched Gavin Newsom as a presidential frontrunner also brought an unwelcome surprise that could haunt the California governor's potential 2028 campaign.

Why it matters: Sen. Alex Padilla caught Newsom off guard Nov. 4 by declaring he wouldn't run for governor — depriving Newsom of his preferred successor on the same day the governor triumphed in a statewide redistricting referendum.

The governor has resisted endorsing any other potential successor ahead of the June 2 primary. There's no clear Democratic frontrunner, and he wants to have a good relationship with whoever wins.

The big picture: The winner of the California race matters a great deal for Newsom's campaign. His governance of the state — and Republican criticism of it — will be critical to a candidacy. He wants a competent governor whom he can work with in 2027 and 2028.

But many strong candidates either did not run or withdrew.
Newsom's Lt. Gov. Eleni Kounalakis dropped out of the race last August, Newsom's Attorney General Rob Bonta decided not to run, former Vice President Kamala Harris did not want the job, and former Rep. Eric Swalwell exited after allegations of sexual misconduct which he has denied.
Newsom privately expressed frustration with a CNN story in April that reported his critiques of all the candidates and told people it didn't capture his true feelings.

Between the lines: Newsom's hand might be forced in the next two weeks. Polls show it's possible for the two Republican candidates to finish first and second in California's "jungle primary" — locking out Democrats from the general election.

That would ensure a Republican succeeds Newsom as governor — a public repudiation of his tenure in a liberal state.
Democrats have been working behind the scenes to boost Democratic turnout to avoid that.
If there is still a real chance of a Republican lockout, Newsom has considered backing one Democrat to try to boost them into the general election.

Each potential Democrat has potential drawbacks or has personally clashed with the governor.

Xavier Becerra, the former Health and Human Services secretary in the Biden administration, has rocketed up in the polls since Swalwell's exit. But some Democrats fear he would be an underwhelming candidate in the general election, where he would likely face former Fox News personality Steve Hilton.

Some Democrats also worry he would be an ineffective governor given that many top officials in the Biden administration felt he shied away from tough assignments and was prioritizing his own personal politics over the larger governing mission (some former top Biden officials like former chief of staff Ron Klain are also backing Becerra).

Tom Steyer, a billionaire who has spent over $100 million in the race, clashed with Newsom's team last fall.

Steyer began running ads during the redistricting ballot measure, Proposition 50, that were at odds with the Newsom team's strategy, with some believing it actually hurt the campaign.

Katie Porter, the former congresswoman, has largely been stuck in single digits or low double digits in the polls after videos of her snapping at an aide and a clash with a reporter went viral last year.

Matt Mahan, the mayor of San Jose who has shot up in the polls with a lot of money from Silicon Valley, built much of his statewide reputation criticizing Newsom on crime and homelessness.

Last year, he wrote an op-ed blasting Newsom's trollish social media strategy, writing "It might be a winning strategy for his presidential campaign, but it's a losing one for improving the lives of Californians."

The intrigue: Mahan has changed his tune on Newsom, whom most California Democrats approve of, since launching his campaign this year.

Mahan told Axios in March: "I think Gavin Newsom is a generational talent. I think he is quite likely to be our party's nominee, and assuming he is, I will look forward to vigorously campaigning for him."
Last month, Mahan also parted ways with his chief strategist Eric Jaye — who had an ugly split with Newsom in 2009 after being a longtime strategist for him.
Jaye did not respond to a request for comment.

Mahan and Newsom also share many donors from the tech community, including billionaire Michael Moritz, who funded Newsom's redistricting ballot measure and is backing Mahan's campaign.

"Matt Mahan is the only Democratic candidate willing to demand massive changes in California," Moritz told Axios. "He is also the only Democratic candidate who agrees with Gov. Newsom's assessment that the proposed wealth tax will be a fiasco for the state."

The bottom line: Mahan has not been effusive about Newsom's tenure.

Asked at a debate this week to describe Newsom's time as governor, Mahan said, "Incomplete."