President Joe Biden’s three-day trip to Southern California, which concluded Friday, featured events with a who’s who of California Democrats — but not Gov. Gavin Newsom.

Many of the state party’s biggest names — including U.S. Sen. Alex Padilla; Los Angeles Mayor Eric Garcetti; U.S. Reps. Karen Bass, Katie Porter and Ted Lieu; and state senator and congressional candidate Sydney Kamlager — turned out alongside the president as he made stops in Los Angeles and Orange County to tout federal infrastructure investments and plans to lower health care costs. Biden also headlined a fundraiser with House Speaker Nancy Pelosi in Los Angeles.

Newsom’s absence was “strange,” given that “it certainly is the tradition that the governor of the state — particularly when the governor’s from the same party — will see the president” when he’s in town, Jessica Levinson, a Loyola Law School professor and California political commentator, said Sunday.

NBC News political director Chuck Todd described the situation to KCRA as a “head-scratcher.”

Newsom spokesperson Alex Stack said Sunday: “The Governor unfortunately had scheduling conflicts. For example, he had an event in Sacramento on Friday morning for his book, in addition to state commitments.”

Levinson said she was skeptical of the governor’s claim: “‘Scheduling conflict’ is the equivalent of ‘I’m dropping out of this political race that I’ll never win to spend more time with my family.’ Nobody really believes it.”

Levinson ran through a few possibilities for why Newsom and Biden may have avoided meeting with each other:

“Biden has been kind of out ahead of Newsom on a couple of issues,” he said. First, the president last month took the rare step of wading into a California legislative battle and endorsing a farmworker unionization bill that Newsom had opposed.

The move apparently infuriated the governor, who ended up signing the bill on the condition that it be significantly amended next year. Second, Biden called on three Los Angeles City Council members to resign for making racist comments and plotting to consolidate Latino political power during last year’s redistricting process — a step Newsom hasn’t taken, though he applauded former council president Nury Martinez’s decision to step down.

Third, Biden has endorsed Rep. Karen Bass for Los Angeles mayor over her opponent, billionaire businessman Rick Caruso — while Newsom thus far has kept out of the race, telling Fox 11 earlier this year that he’s known both candidates for years and has “deep respect” for both.

“Biden may feel that Newsom is waiting in the wings … There could be a little personal bad blood because Newsom has become such a national presence and seems to be positioning himself to fill a potential void,” Levinson speculated.

Newsom’s efforts to amplify his national profile — including by slamming the Democratic Party for failing to aggressively counteract the GOP on such hot-button topics as abortion and LGBTQ rights — have seemingly irked some members of the Biden administration.

But Newsom, who insists he has “sub-zero” interest in a presidential run, has repeatedly praised Biden, saying that he’s delivered “a master class … on substance and policy” in his first two years in office.

Asked whether potential political animosity between Biden and Newsom may have foreclosed a meeting between the two men, Stack said: “No.”

Meanwhile, the governor’s office on Friday published a recap of events showing how “the Newsom administration was hard at work this week taking action for Californians across a variety of issues,” including breaking ground on a 10,000-mile broadband network to help expand high-speed internet access and cracking down on illegal cannabis operations.

At the end of the day, Newsom‘s reticence on high-profile Los Angeles issues may simply reflect his expected easy path to victory in California’s Nov. 8 election over gubernatorial candidate Republican state Sen. Brian Dahle of Bieber, Levinson said.

“Where’s the political upside for him to get involved?” Levinson asked. “I mean, nobody’s going to vote for Brian Dahle because (Newsom) didn’t take a strong stand in the LA mayor’s race or because he didn’t say vigorously enough that he condemns what happened in Los Angeles” on the city council.”