Despite renewed anxiety over the president’s age, party officials and pollsters say swapping him out is a bad idea, and nearly impossible without Biden’s sign-off.

“No one who’s done this at this level thinks that removing the sitting president of the United States, who’s a Democrat, from your ballot is remotely plausible,” said Cornell Belcher, one of former President Obama’s pollsters. “It’s completely absurd.”

A special counsel questioned Biden’s mental acuity last week in a report that explained why criminal charges were not warranted for possession of classified documents, offering fresh fodder to critics of the president and fueling concerns about his ability to serve another four years in office.

Hosts of ABC’s “The View” kindled the conversation on Friday in an on-air debate over Biden’s candidacy and whether Vice President Kamala Harris or Newsom would be better options for the party. Republican Chris Christie, the former New Jersey governor and former presidential candidate, and other political pundits have suggested Democrats should trade Biden for another candidate.

Here are five reasons why Biden — and not Newsom — is all but certain to remain the Democratic presidential nominee:

1) The days of smoke-filled rooms are over

Biden, like most incumbent presidents, is in control of the party, meaning people who work for the Democratic National Committee and other party organs are aligned with his campaign operation. The deadline for challenging him in a Democratic primary has expired in most states, including California, and he faces only scant opposition. He could be replaced if he chose to step aside and free his delegates at the party’s national convention in Chicago this August, the type of scenario that hasn’t happened in decades.

“I’m sure there are a lot of people who might think of themselves as plan B,” said David Axelrod, Obama’s chief strategist. “But plan A seems to be pretty determined to stay in the race.”

Even under the remote scenario in which Biden pulls out and leaves an open convention, chaos would be more likely than consensus.

“There is this mythology that we’re living in the 1940s and a bunch of party leaders come together and say, ‘That’s our guy,’” Axelrod said. “That’s not the way it works anymore. There would be a number of people who would surface. I rate the odds of that exigency very, very low.”

Another Democratic operative who has connections to top donors in California and major East Coast hubs said there has been lingering chatter about seeking a replacement since last year, but no serious discussion. Most people recognize the need to move on from the replacement fantasy, said the operative, who requested anonymity to avoid antagonizing party officials.

Belcher said the loudest intraparty talk has been fueled by progressives, the same people he said made a similar argument ahead of Obama’s second term.

But even some of the most liberal in the Democratic Party pushed back on the idea.

R.L. Miller, a DNC delegate from California and founder of Climate Hawks Vote, described the possibility that Biden steps out of the race as “an extraordinarily unlikely scenario” and the odds that the party would tap Newsom to replace him as even more remote.

“You might as well write about the possibility of asteroids crashing out of the sky and wiping out all light west of the Hudson where ‘The View’ is filmed,” Miller said.

2) The time has passed

Hans Noel, an associate professor of government at Georgetown University, said if Biden steps down today, Democrats seeking to replace him could scramble to run in the handful of states where primary ballot access deadlines have not passed. The decision to select a replacement would still be kicked to the Democratic National Convention this summer.

Delegates would probably elect Biden on the first ballot. Biden would have to turn it down. Delegates would vote for a replacement on a second ballot and so on until a nominee was chosen.

If Biden announced his plans in advance, replacement candidates would have a little time to campaign. If he decides to turn down the nomination at the convention, it would be even messier.

“All of the people who are delegates now are free to vote for whoever they think is the right candidate,” Noel said of that scenerio.

The process could look similar to the 1968 Democratic National Convention, which was also held in Chicago. Months before the convention, then President Lyndon B. Johnson announced that he would not seek reelection and candidate Robert Kennedy was killed after winning the Democratic primary in California.

Amid protests, violence and an effort to nominate an actual pig, delegates chose Hubert Humphrey, Johnson’s vice president, as the Democratic nominee.

Biden withdrawing after the convention could trigger an even more uncertain and unprecedented process.

3) Newsom remains on Team Biden, too

“A gazillion percent,” said Sean Clegg, a senior political advisor to Newsom. “If President Biden asks this guy to do anything, he’s going to do it and give everything he has to support the ticket.”

Clegg said Newsom’s camp isn’t discussing the possibility of replacing Biden because it isn’t happening.

That might seem hard to believe from a governor who appears to relish the national spotlight, is actively attempting to boost his profile with voters across the country and successfully prodded his Republican rival, Florida Gov. Ron DeSantis, to debate him on Fox News late last year.

At an Asia-Pacific Economic Cooperation summit in San Francisco in November, Biden commended Newsom’s performance as governor and, perhaps inadvertently, stoked the speculation.

“Matter of fact, he could be anything he wants,” Biden joked. “He could have the job I’m looking for.”

Newsom, who repeatedly denies having presidential ambitions, has been careful to answer questions about his candidacy with praise for Biden.

“I’ll go to the ends of the earth for this guy,” Newsom said in an MSNBC interview.

4) What about the sitting vice president?

Among Democratic politicians, Miller mentioned Harris, Michigan Gov. Gretchen Whitmer, Illinois Gov. J.B. Pritzker and Newsom as people she would expect to try out for the job if Biden suffered a serious health problem.

“Of the four names I mentioned, I would put Newsom dead last,” she said.

Harris, she said, is best positioned for the job as Biden’s vice president. Whitmer and Pritzker would have a shot at winning swing states.

Harris has her own problems, though. Only 40% of voters view her favorably, compared with 55% who hold a negative view, according to the Los Angeles Times polling tracker. That’s roughly the same as Biden’s polling average.

Her first campaign for president in 2020 flamed out before the primaries and she’s been targeted relentlessly by conservatives, who have tried to cast her as a dangerous heir apparent if Biden drops out or falters during a second term.

5) Newsom symbolizes California liberalism

A recent Los Angeles Times-Leger poll found 50% of American adults — including 30% of Democrats — believe the state is too liberal. The poll found sharp differences between how Californians and people outside the state view issues such as climate, race and gender. Nearly half of Californians say abortion should be legal in all cases, compared with a quarter of adults nationwide.

The same poll found Newsom was viewed positively by about a third of Americans, negatively by another third and and unknown by everyone else. Those numbers are decent in a sharply polarized environment. But any Democrat who became the nominee would have to withstand a new onslaught of criticism.

“If you put up a choice of Joe Biden against some mythical perfect Democrat, the mythical perfect Democrat wins,” said one operative with ties to the DNC. “But there’s no actual Democrat that voters can agree on as an alternative.”