SACRAMENTO, Calif. (AP) — California Gov. Gavin Newsom says there's no chance “on God's green earth” he's running for president in 2024, but he wants to make clear that Florida Gov. Ron DeSantis, who is running, is “weak” and “undisciplined” and “will be crushed by Donald Trump."

DeSantis, meanwhile, likes to mock Newsom's apparent “fixation” on Florida while insisting that the Democratic governor's “leftist government" is destroying California.

Welcome to one of the fiercest rivalries in U.S. politics, featuring dueling term-limited governors who represent opposite ends of the ideological spectrum and lead two of the nation's largest and most influential states. Newsom and DeSantis almost certainly won't face each other on any ballot in 2024, but in many ways, they are defining the debate from their corners of America as the presidential primary season gets underway.

Newsom addressed both his contempt for DeSantis and loyalty to President Joe Biden — even after Tuesday's revelations that the president's son, Hunter, was pleading guilty to tax offenses and a gun charge — in an interview just as the Florida governor launched a two-day fundraising trek spanning at least five stops across California. The Golden State has become one of DeSantis' favorite punching bags as he tries to avoid a direct confrontation with his chief Republican presidential rival, Trump, and the former president's escalating legal challenges.

“He's taking his eye off the ball," Newsom said of DeSantis' escalating attacks against him. “And that's not inconsistent with my own assessment of him, which is he is a weak candidate, and he is undisciplined and will be crushed by Donald Trump, and will soon be in third or fourth in national polls.”

Representatives for DeSantis did not make the governor available for an interview. Beneath the war of words, however, strategists in both parties suggest there may be a mutually beneficial dynamic at play. As they jab at each other's policies and personalities through comments in the press and on social media, the governors are scoring points with their respective political bases, raising money and expanding their national brands.

Both men issued fundraising appeals Monday going after the other by name.

But it's not all helpful.

Newsom, in particular, is facing nagging questions about his presidential ambitions less than a week after DeSantis dared him to “stop pussyfooting around” and launch a primary challenge against Biden.

The California governor, whose second and final term concludes at the end of 2026, has seen his national profile grow since he easily beat back a recall attempt in 2021 and cruised to reelection last fall. He finished the midterm campaign with roughly $16 million in the bank. And in March, he channeled $10 million to a new political action committee he's calling the Campaign for Democracy.

All the while, Newsom's team has been moving deliberately to avoid the perception that he's running a shadow presidential campaign just as Biden ramps up his political activities.

For example, Newsom's new PAC is initially focusing on challenging Republican leaders in deep-red states that are largely irrelevant in the 2024 presidential race. He campaigned in Alabama, Arkansas and Mississippi in April on his first trip associated with the PAC.

Newsom is expected to avoid battleground states or key presidential primary states for the foreseeable future, his allies say.

At the same time, the California governor and his team have been in regular contact with Biden and his top aides, including Jen O'Malley Dillon, who managed the president's 2020 campaign and serves as deputy White House chief of staff. A Biden campaign official said the president's team coordinates closely with Newsom.

“Newsom is not going to run against Joe Biden and never would. But life is long, and Newsom is one of the prominent national Democrats. It’s part of that role to have these big national battles,” longtime Newsom adviser and friend Nathan Ballard said of the feud with DeSantis.

“There is the 2024 election, and then there is a 2028 election,” Ballard added.

Indeed, veteran Democratic consultant Roy Behr, whose clients included former California Sen. Barbara Boxer, said the two governors are engaged in what could become an early preview of the 2028 presidential contest.

“It’s not inconceivable that four years from now, these two guys could be their respective parties’ nominees,” he said. In tangling with DeSantis, who is 44, the 55-year-old Newsom is building his national brand and visibility and is “certainly trying to create opportunities for himself.”

Sacramento-based Democratic consultant Andrew Acosta said he expected the ongoing rivalry to continue given that it’s beneficial for both politicians with their core supporters. He described Newsom and DeSantis as “frenemies."

"They both get points off it,” Acosta said. “There is a hard core of voters on both sides who think this is great.”

While polling shows that many Democrats don’t want the 80-year-old Biden to seek a second term, Newsom said there are no circumstances in which he would challenge the sitting president of his own party.

“Not on God’s green earth, as the phrase goes,” Newsom said in the weekend interview, adding that he would be with Biden on Monday and hosting a fundraiser for him Tuesday. "I have been pretty consistently — including recently on Fox News — making the case for his candidacy.”

On Tuesday, Newsom reaffirmed his support for Biden shortly after news surfaced that the president's son, Hunter, reached a plea deal with federal prosecutors on charges he failed to pay federal income tax and illegally possessed a weapon.

“Hunter changes nothing,” Newsom told the AP, noting that he was spending the day with Biden.

DeSantis did not plan to make any public appearances during his California fundraising tour, which included stops in Sacramento and the Bay Area on Monday and continues Tuesday with events planned for San Diego, Orange County and Los Angeles.

Over the weekend in Nevada, DeSantis noted that he's seen a surge of “disgruntled Californians” moving to Florida.

“Why would you leave like a San Diego to come to say, Jacksonville, Florida? I see people doing that,” DeSantis told thousands of conservative activists at a weekend gathering close to the California border. “It’s because leftist government is destroying that state. Leftist government is destroying cities all over our country. It’s destroying other states.”

Former Nevada attorney general Adam Laxalt, who hosted the weekend event and leads the pro-DeSantis super PAC, said the policy contrast between the leaders of Florida and California is “a debate that our whole country needs to have.”

“California has been the model for many leftist policies. I would take the contrast between Florida’s policies and its results led by Gov. DeSantis and the California policies, any day of the week," Laxalt said in an interview. “We can already see what leftist policies do.”

Both DeSantis and Newsom took office in 2019 and won reelection for their second and final terms in 2022. While in office, both have been buoyed by multiple billion-dollar budget surpluses and the help of statehouses controlled by their own party that supercharged their agendas.

In California, Newsom expanded the state’s Medicaid program to cover all eligible adults, regardless of their immigration status. He signed a raft of legislation to make it easier to get an abortion, including authorizing $20 million in state spending to help people from other states travel to California. When the U.S. Supreme Court declined to strike down an abortion law in Texas that was enforced by private lawsuits, Newsom signed a similar law in California — only he made it about guns.

And earlier this month, he proposed amending the U.S. Constitution to institute what he called a “reasonable” waiting period for all gun purchases, a ban on so-called assault rifles, universal background checks and raising the minimum age to buy a firearm to 21.

“I think Gavin Newsom is a very useful foil for Ron DeSantis, quite frankly,” said Lanhee Chen, a California Republican who attended one of DeSantis’ five California fundraisers this week. “The more kinds of crazy things that Newsom does — at least, crazy in the in the eyes of Republican voters — the more I think Ron DeSantis frankly benefits as somebody who seen as a counterweight to that.”

In Florida, DeSantis has leaned into cultural conservative issues in what he calls his “war on woke.”

Earlier this month, his administration flew groups of migrants from Texas to Sacramento to draw attention to the influx of Latin American immigrants trying to cross the U.S.-Mexico border. He did the same last fall, sending dozens of immigrants from Texas to Martha’s Vineyard, which he often highlights during his stump speeches.

DeSantis also signed and then expanded the Parental Rights in Education bill — known by critics as the “Don’t Say Gay” law, which bans instruction or classroom discussion of LGBTQ+ issues in Florida public schools for all grades. He seized control of Disney World’s governing body after the company publicly opposed the law.

The Florida governor this year also signed a law banning abortions at six weeks, which is before most women realize they’re pregnant. And he took control of a liberal arts college that he believed was indoctrinating students with leftist ideology.

While DeSantis does not have the legal entanglements that Trump faces, Newsom said Democrats may be wrong to assume the former president would be an easier candidate to defeat in the 2024 general election.

“I see deep weakness — I refer to it often — weakness with DeSantis masquerading as strength," Newsom said. "I think he’d be a more favored candidate. But I’ll leave that judgment to more objective minds.”