Stephen L. Carter, Bloomberg

For those searching for a legal process to keep Donald Trump from returning to the Oval Office, I have a simple suggestion: Lobby President Joe Biden to pardon him.

Seriously.

The legion of Never Trumpers has spent years hoping that an impeachment trial or a courtroom verdict might somehow keep the controversial former president from making another run. That tactic isn't likely to work. Statutes that disqualify offenders from public office are surely unconstitutional as applied to the presidency, because the qualifications are spelled out in the Constitution.

But a pardon is different. Presidents can attach conditions. One who accepts the pardon agrees to the conditions — and those conditions, unless they demand an illegal act or are impossible to perform, become legally binding.

Imagine, then, that Biden offered Trump a pardon in exchange for a promise not to seek public office again. If Trump said yes and then ran for office anyway, the underlying pardon would become null and void.

Conditional pardons have been part of the nation's political life for two centuries. In 1829, for instance, President Andrew Jackson issued a pardon on the condition that the recipient undertake "some beneficial trade" — in short words, get a job. Other pardons have included everything from enlisting in the armed forces to staying out of the country.

Challenging the conditions has proved fruitless. In 1971, President Richard Nixon commuted convicted Teamsters Union leader Jimmy Hoffa's prison sentence, conditioned on Hoffa's agreement not to engage in union politics. After his release, Hoffa filed a federal lawsuit seeking to overturn the condition. Pointing to the president's "unfettered discretion" in exercising the pardon power, the court dismissed the action. Moreover, as the courts have long held, the president (or his successor) is the "sole judge" of whether the conditions have been violated.

One might object that a pardon conditioned on Trump's agreement not to seek elective office would violate his constitutional rights. After all, although the Supreme Court has danced around the issue, many scholars consider running for office a fundamental freedom.

In practice, however, presidents have regularly used the pardon power in ways that trample even better-established constitutional rights.

The First Amendment, for instance.

President Bill Clinton granted clemency to the imprisoned members of FALN, the Puerto Rican separatist group accused of over 100 bombings, on the condition that they renounce violence. President Abraham Lincoln's offer of amnesty to Southern rebels required that they take an oath of loyalty to the Union. Some recipients were also required to agree to clear with the US military any correspondence they proposed to send to a resident of the South.

In short, conditional pardons have a long history; the conditions are fully enforceable; and their violation means that the pardon evaporates. Should Trump accept a conditional pardon, he'd be stuck with the terms.

Don't get me wrong. This isn't an our-long-national-nightmare-is-over argument. By the time Nixon resigned in August 1974, his popularity had collapsed. Only 24% of those surveyed wanted him to remain in office. The current moment is far from analogous. No matter how passionately some would like Trump to disappear, his influence is unlikely to wane soon. Recent polls even have him beating Biden. My point is simply that who are most strongly anti-Trump should be pressing for a pardon.

Incensed MAGA supporters, on the other hand, should bear in mind that Biden can only offer the pardon; Trump remains free to say no. Although presidents have now and then pardoned people against their will, nobody thinks the chief executive can impose a conditional pardon without the consent of the recipient. Otherwise, as critics have warned, "a conditional pardon can be an effective way for a president to neutralize a political enemy."

In this sense, the pardon would offer both to Trump's opponents and his supporters a test of their competing faiths.

Those who despise him would have to decide which they prefer: to get him into an orange jumpsuit or to keep him out of the Oval Office. Those who believe that the multiple investigations of Trump represent a partisan effort to put their candidate aside would likely urge him to reject the offer, take his chances in court and run again in 2024. If he nevertheless were to accept the pardon with its conditions, supporters might be justified in wondering whether, behind the bluster, lies a kernel of guilt.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

Stephen L. Carter is a Bloomberg Opinion columnist. A professor of law at Yale University, he is author, most recently, of "Invisible: The Story of the Black Woman Lawyer Who Took Down America's Most Powerful Mobster."