(NewsNation) — While California Democratic Gov. Gavin Newsom has denied that his sights are set on the White House, political experts believe it’s not a question of if he will run for president, but when.

So far, only two long-shot candidates have decided to challenge President Joe Biden for the Democratic nomination. No Democrat has ever jumped from the California governor’s mansion to the White House, but many believe Newsom would like to be the first.

“My sense is that the governor is trying to leave his options open,” Eric Schickler, a political science professor at the University of California, Berkeley, told The Hill. “I don’t think there’s any expectation at all he would challenge Joe Biden for reelection.”

Schickler added: “Building a national profile now, the most likely scenario where that really comes to fruition is for 2028.”

In recent weeks, Newsom has been on a tour speaking in red states and now has made a call to toughen gun laws across the nation, which has led experts to question if he’s just making headlines or if it’s the unofficial start of a 2024 bid.

Newsom on Thursday proposed a 28th amendment to the U.S. Constitution that, if passed, would restrict access to gun ownership in all 50 states.

Newsom outlined his plan to pursue the amendment to implement four gun control safety regulations into the Constitution — raising the minimum age to purchase firearms from 18 to 21, implementing universal background checks, instituting a “reasonable” waiting period for gun purchases and preventing civilians from buying “assault weapons.” 

“This will guarantee states as well the ability to enact common sense gun safety laws while leaving the Second Amendment intact and respecting America’s gun-owning tradition,” Newsom said in an ad promoting his Campaign for Democracy.

The ad has left many wondering whether it’s a signal that Newsom may throw his hat in the ring to challenge Biden in the 2024 Democratic primaries.

Yet, the push for a 28th constitutional amendment isn’t the only sign Newsom may be considering a presidential run. In recent weeks, the governor has hit the road for a red state speaking tour where he’s encouraged Democrats to get more aggressive fighting Republicans in the national culture war and battling Texas Republican Gov. Greg Abbott and Florida Republican Gov. Ron DeSantis.

Earlier this week, Newsom took his burgeoning feud with DeSantis to a new level, calling the 2024 Republican presidential candidate a “small, pathetic man” after the Florida governor sent a plane full of migrants to Sacramento.

Schickler emphasized his doubts that the governor would be a 2024 candidate unless Biden is somehow unable to run.

“In that case, it’d be a very wide open Democratic field, and I think that Governor Newsom would be one of the people who would nationally be talked about as a serious contender,” the professor said.

Daniel Schnur, a Republican-turned-independent political strategist, echoed these sentiments, describing the governor as both “ambitious” and “impatient,” but “also very smart.”

“He knows that challenging a sitting president of his own party is not going to be good for his own political prospects. So if he needs to, he’ll wait another four years,” said Schnur, who teaches at both Berkeley and the University of Southern California.

So far, Newsom’s office has steadfastly denied that the governor is considering running against Biden.

Newsom’s current term as governor would end in January 2027, setting him up for a potential run in 2028.

A March Quinnipiac University Poll found that 70% of California voters don’t want Newsom to enter the 2024 race, compared to 22% who do want him to run. A majority of California Democrats, 54%, want Newsom to stay out of the Democratic Presidential Primary.

Newsom easily survived a recall election in September 2021, winning 61.9 percent of the vote.

NewsNation reached out to Newsome’s office for comment on a possible 2024 run, but they have not responded.

Former California Govs. Jerry Brown (D) and Pete Wilson (R) both lost presidential bids in 1992 and 1996, respectively.