Walter Dellinger was head of the Office of Legal Counsel from 1993 to 1996 and acting U.S. solicitor general from 1996 to 1997.

What does the nation do if it turns out that a president of the United States has committed serious crimes that a prosecutor can prove beyond a reasonable doubt? One possible resolution would be to offer a plea bargain in which the commander in chief agreed to resign the presidency in exchange for utmost leniency. Perversely, the more financially corrupt or psychologically unstable the White House occupant, the greater his or her bargaining power: Only if you let my client go scot-free, a president’s lawyers could argue, will you be allowed to pry the nuclear codes from his hands.

That is a powerful bargaining chip but one with an expiration date. At the strike of noon on his successor’s Inauguration Day, when the (former) president’s Air Force One turns into a pumpkin, he loses that leverage and becomes like any other citizen before the bar of justice. That gives a provably corrupt president a great incentive to end his term early — and on his terms.

The end of Spiro T. Agnew’s vice presidency is instructive — and provides a good example for why we should be able to indict a sitting president.

On Oct. 10, 1973, Agnew resigned as vice president of the United States and pleaded guilty to one count of tax evasion. He was sentenced to a fine of $10,000 and a period of unsupervised probation. He basically walked out of the courtroom and into a life of playing golf and making money peddling influence. As the tale is told in the excellent 1974 book by Richard M. Cohen and Jules Witcover, “A Heartbeat Away: The Investigation and Resignation of Spiro T. Agnew” (and in the terrific podcast “Bag Man”), this bargain was highly controversial. The sentence was extraordinarily light for crimes so serious committed by an official so high in the nation’s trust.

Agnew’s corruption began when he served as Baltimore County executive and continued throughout his term as governor of Maryland. For years, Agnew used his government offices for bribery and extortion, steering government contracts in exchange for money. After he was elected vice president, the payments continued. Most shockingly, packets of cash were delivered to Agnew at the White House itself. The evidence of Agnew’s guilt was overwhelming.

But what was to be done? Impeachment by the House and a trial in the Senate did not seem to be a viable course of action. In fact, Agnew sought to initiate an impeachment process in the belief that the charges would become enmeshed in a cumbersome political process that could offer him more protection than risk. House Speaker Carl Albert declined Agnew’s request, saying the criminal process should proceed. (In a related matter, Solicitor General Robert H. Bork rejected Agnew’s argument that a sitting vice president could not be indicted.)

Attorney General Elliot Richardson authorized a plea bargain so favorable to Agnew that the young lawyers in the U.S. attorney’s office who had been investigating the case were understandably dismayed. Richardson, however, was looking at a larger context.

President Richard M. Nixon’s Watergate scandal was simultaneously exploding, and Nixon seemed to be imploding. If Watergate took down the president, it was imperative that Agnew be out of the line of succession. The urgency of the situation, and the imperative to avoid having a corrupt felon take over the presidency, gave Agnew enormous bargaining power. And he used it.

But the most significant impediment to holding a president accountable to justice is the statute of limitations. Generally, most federal crimes must be charged within five years or forever be barred. For crimes committed while the president is in office, there will be time enough at the end of the president’s term. But if a president engaged in financial crimes before taking office, or committed crimes to gain that office, the time for charging those crimes could well expire before his or her term concluded.

That is one of the reasons a grand jury should be permitted to indict a sitting president, as long as all further proceedings are postponed while he or she is in office. Unless an indictment could issue against a sitting president, there would be a perverse incentive for an alleged White House felon to seek reelection simply to avoid indictment while waiting for the statute of limitations to expire on crimes he had committed. The history of the Justice Department’s conflicting positions on this question does not categorically foreclose issuing an indictment against a sitting president.

Even where lawful, the use of the criminal process against sitting or former presidents should be undertaken with caution. In an ideal world, what our presidents and presidential candidates should most fear are voters, not prosecutors. But where the crimes are extremely serious and the proof compelling, the principle that no one is above the law may leave little choice but to proceed to court.

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