What Happens if a Presidential Candidate Is Convicted?

Not since Eugene V. Debs campaigned from a prison cell more than a century ago has the United States experienced what might now happen: a prominent candidate with a felony conviction running for president. And never before has that candidate been someone with a real chance of winning.

Former President Donald J. Trump faces no campaign restrictions. Though he has been charged with dozens of felonies across two cases, one federal and one in New York, verdicts are a long way off. And there are many uncertainties, including whether the proceedings will hinder Mr. Trump’s campaign in practical ways or begin to hurt him in the polls in a way they have not so far.

But if he is convicted on any of the felony counts, things get more complicated — and the Constitution and American law have clear answers for only some of the questions that would arise.

Others would bring the country into truly uncharted territory, with huge decisions resting in the hands of federal judges.

Here is what we know, and what we don’t know.

Can Trump run if he is convicted?

This is the simplest question of the bunch. The answer is yes.

The Constitution sets very few eligibility requirements for presidents. They must be at least 35 years old, be “natural born” citizens and have lived in the United States for at least 14 years.

There are no limitations based on character or criminal record. (While some states prohibit felons from running for state and local office, these laws do not apply to federal offices.)

Would his campaign be restricted?

To offer an obvious understatement, it would be logistically difficult to run for president from prison. No major-party candidate has ever done it. Mr. Debs ran for the Socialist Party in 1920 and received about 3 percent of the vote.

But Mr. Trump’s campaign staff could handle fund-raising and other campaign activities in his absence, and it is very unlikely that Mr. Trump could be disqualified from appearing on ballots.

The Republican and Democratic Parties have guaranteed spots on general-election ballots in every state, and the parties tell election officials whose name to put in their spot. States could, in theory, try to keep Mr. Trump off the ballot by passing legislation requiring a clean criminal record, but this would be on legally shaky ground.

“We let states set the time, place and manner” of elections, said Jessica Levinson, a professor at Loyola Law School who specializes in election law, “but I think the best reading of our Constitution is you don’t let the state add new substantive requirements.”

While that view is not universal among legal experts, it won in court in 2019, when California tried to require candidates to release their tax returns in order to appear on primary ballots. A federal district judge blocked the rule, saying it was most likely unconstitutional. The California Supreme Court also unanimously blocked it as a violation of the state constitution, and the case never reached the U.S. Supreme Court.

Could he vote?

Probably not.

Mr. Trump is registered to vote in Florida, and he would be disenfranchised there if convicted of a felony.

Most felons in Florida regain voting rights after completing their full sentence, including parole or probation, and paying all fines and fees. But it is highly unlikely that Mr. Trump, if convicted, would have time to complete his sentence before Election Day.

Since Mr. Trump also has a residence in New York, he could switch his voter registration there to take advantage of its more permissive approach: Felons in New York can vote while on parole or probation. But, as in Florida and almost every other state, they are still disenfranchised while in prison.

So if Mr. Trump is imprisoned, he will be in the extraordinary position of being deemed fit to be voted for, but unfit to vote.

What happens if he is elected from prison?

No one knows.

“We’re so far removed from anything that’s ever happened,” said Erwin Chemerinsky, a constitutional law expert at the University of California, Berkeley. “It’s just guessing.”

Legally, Mr. Trump would remain eligible to be president even if he were imprisoned. The Constitution says nothing to the contrary. “I don’t think that the framers ever thought we were going to be in this situation,” Professor Levinson said.

In practice, the election of an incarcerated president would create a legal crisis that would almost certainly need to be resolved by the courts.

In theory, Mr. Trump could be stripped of his authority under the 25th Amendment, which provides a process to transfer authority to the vice president if the president is “unable to discharge the powers and duties of his office.” But that would require the vice president and a majority of the cabinet to declare Mr. Trump unable to fulfill his duties, a remote prospect given that these would be loyalists appointed by Mr. Trump himself.

More likely, Mr. Trump could sue to be released on the basis that his imprisonment was preventing him from fulfilling his constitutional obligations as president. Such a case would probably focus on the separation of powers, with Mr. Trump’s lawyers arguing that keeping a duly elected president in prison would be an infringement by the judicial branch on the operations of the executive branch.

He could also try to pardon himself — or to commute his sentence, leaving his conviction in place but ending his imprisonment. Either action would be an extraordinary assertion of presidential power, and the Supreme Court would be the final arbiter of whether a “self pardon” was constitutional.

Or President Biden, on his way out the door, could pardon Mr. Trump on the basis that “the people have spoken and I need to pardon him so he can govern,” Professor Chemerinsky said.

What if he’s elected with a case still in progress?

Again, no one knows. But a likely outcome would be that a Trump-appointed attorney general would withdraw the charges and end the case.

The Justice Department does not indict sitting presidents, a policy outlined in a 1973 memo, during the Nixon era. It has never had reason to develop a policy on what to do with an incoming president who has already been indicted. But the rationale for not indicting sitting presidents — that it would interfere with their ability to perform their duties — applies just as well in this hypothetical scenario.

“The reasons why we wouldn’t want to indict a sitting president are the reasons we wouldn’t want to prosecute a sitting president,” said Professor Chemerinsky, who has disagreed with the department’s reasoning. “My guess is, if the Trump prosecution were still ongoing in some way and Trump were elected, the Justice Department — which would be the Trump Justice Department — would say, ‘We’re following the 1973 memo.’”

Like so much else here, this would be legally untested, and it is impossible to say what the Supreme Court would do if the question reached it.

In its Clinton v. Jones ruling in 1997, the court allowed a lawsuit against President Bill Clinton to proceed. But that case was civil, not criminal, and it was filed by a private citizen, not by the government itself.

Charlie Savage contributed reporting.