It’s not entirely clear why, but more voters now disapprove of how he’s handling his job (49%) than approve (44%), based on a nonpartisan poll.

This is a stunning tumble since February when the same polling outfit — the UC Berkeley Institute of Governmental Studies — found just the opposite. Since then, there has been a significant 10-percentage-point increase in disapproval of Newsom and an 11-point plunge in approval.

Veteran IGS pollster Mark DiCamillo told the Los Angeles Times — co-sponsor of the survey — that Newsom is “kind of taking on a new persona. He’s no longer just the governor of California. He’s a spokesperson for the national [Democratic] party and basically voters are being asked to react to that.”

Many are reacting with a frown.

DiCamillo elaborated in his poll report, writing: “Newsom’s recent actions in taking a much more active role in national Democratic politics appear to be related to his recent decline…. Voters here hold decidedly mixed views about taking on this role at a time when California is facing increasing budgetary challenges and is dealing with a host of other pressing problems.”

The pollster didn’t mention the other problems, but most people are quite familiar with the list:

Homelessness hasn’t really improved on Newsom’s watch.

Neither has the plague of unaffordable housing.

He pledged to penalize Big Oil for gasoline price gouging, but that hasn’t happened. Gas prices fluctuate but are always higher than in other states.

This is a high-tax state, contributing to exorbitant living costs.

Downtowns in some cities — San Francisco and Sacramento, for example — have deteriorated, largely because they haven’t recovered from the governor’s forced office shutdowns during the pandemic. Students haven’t caught up from classroom closures and probably never will.

None of this is entirely Newsom’s fault, but he’s the guy voters put in charge of state government.

It’s my guess — based on covering several chief executives — that Californians expect their governor to focus on the job he was elected to do rather than traveling the nation and world playing national and global politics, perhaps setting himself up for a future presidential race.

Newsom’s predecessor, Jerry Brown, is the prime example. In his first tenure as governor, he ran twice for president and failed miserably. His popularity fell and the Democrat lost a Senate bid he should have won in 1982. During his second gubernatorial stint, Brown focused on his day job and earned high marks.

Newsom says he’s not interested in the presidency — indicating it’s the furthest thing from his mind — but I suspect few people buy that. And he’s covered by the news media as a potential White House contender in 2028 if not next year, seemingly to the delight of his inner circle.

One turnoff for me is the governor’s press office promoting Newsom group meetings as “fireside chats.” This either is a display of irreverence for history and the great FDR or just simple ignorance.

In the IGS poll, California voters gave Newsom decent marks for his recent trip to China — 50% approval and 39% disapproval. But the framing of the question almost guaranteed the positive responses. Those interviewed were told — as the public was by Newsom — that the trip’s purpose was “to discuss how California and China can work together to address climate change issues.”

“That’s the reason [the polling numbers] came back positive,” DiCamillio says. “It’s about climate change. After the trip was completed, it looked like a lot more than that.”

Newsom seemed to be trying to play the role of global statesman, hamming it up on the world stage in an effort to burnish his resume for a future presidential bid.

If the governor really wants to lead on a global issue, he could speak out forcefully — preferably in a televised speech — against the antisemitic incidents on California university campuses stemming from the Israeli-Hamas war.

In the poll, voters were divided about his “more prominent role in national Democratic politics … and going to events outside of the state to criticize the Republican Party and its political leaders.”

Voters split almost evenly: 45% in favor, 43% opposed.

Newsom has been raising campaign money for President Biden and Democratic candidates in other states and fighting the culture wars with conservatives across America — veering outside his assigned lane as governor.

“As a general rule, it’s not great politics here in California from a voter perspective to be off discussing national issues,” DiCamillo says. “It’s best to pay attention to state issues. And that’s not what Newsom wants to talk about.”

In truth, Newsom does talk a lot about state problems. But his zeal these days seems to be on national politics.

Newsom’s negative job rating also surely results, in large part, from the voters’ current sour mood that tends to settle on politicians in high office, President Biden included.

A poll released Wednesday by the nonpartisan Public Policy Institute of California found that 56% of voters think the state is headed in the wrong direction. Two-thirds believe the American Dream doesn’t hold true. And three-fourths expect today’s children to grow up to be worse off financially than their parents.

“Presidents and governors get blamed for the economy and credit for the economy,” says PPIC pollster Mark Baldassare. “They probably don’t deserve either.”

At any rate, Newsom should stick more to the job he asked for and voters gave him.