Is it constitutional to hold an impeachment trial for a former president?

The Constitution is not at all clear about whether Trump remains vulnerable to impeachment.

No one knows whether the Constitution permits the Senate to hold an impeachment trial for former President Donald Trump, now that Trump no longer holds office.

To be sure, there is a bevy of legal scholarship discussing this question. And, as a recent report by the nonpartisan Congressional Research Service notes, “most scholars who have closely examined the question have concluded that Congress has authority to extend the impeachment process to officials who are no longer in office.”

But while the Constitution mentions impeachment six times, the text of the document provides little clarity on whether the Senate’s power to try an impeached official terminates when that official leaves office.

The question of whether Trump can still be convicted by the Senate matters because the Constitution permits an impeached official to be permanently disqualified from holding office. So, if Trump can face an impeachment trial, the Senate could potentially forbid him from running for president again in 2024 — or in any subsequent election.

And, while the weight of scholarship does suggest that Trump is still vulnerable to impeachment, several Republican senators have already latched onto the minority position — the view that former officials are immune from impeachment — as a reason to vote against conviction. As Sen. Joni Ernst (R-IA) said of impeachment shortly before Trump left office, “my overall question is: Why are we doing this when the president is out of office tomorrow?”

She added that she doesn’t “think” that it would be constitutional to try Trump after he leaves office.

Trump’s fate, in other words, could hinge on the answers to two questions: whether Trump is still vulnerable to an impeachment proceeding, and whether enough senators claim that he is now immune from such proceedings to prevent his conviction.

So is it constitutional to convict Trump or not?

J. Michael Luttig, a conservative former federal judge, recently laid out the constitutional case against convicting former officials in the Washington Post.

The purpose of the impeachment power, Judge Luttig claims, is “to remove from office a president or other ‘civil official’ before he could further harm the nation from the office he then occupies.” So once an official no longer occupies their office, the case against them becomes moot — a private citizen cannot “further harm the nation” using the powers of a federal officeholder.

To support this argument, Luttig points to two constitutional provisions. One provides that the president “shall be removed from Office on Impeachment for, and Conviction of, Treason, Bribery, or other high Crimes and Misdemeanors,” and another provides that “Judgment in Cases of Impeachment shall not extend further than to removal from Office, and disqualification to hold and enjoy any Office.”

Yet, while the first of these provisions does say that the president can be removed from office through impeachment, and the second limits the consequences of being convicted by the Senate, neither explicitly states that a former official can or cannot be convicted by the Senate. And, as noted above, Luttig’s view is the minority position among legal scholars.

Luttig suggests that the only purpose of impeachment is to remove an official before that official can use their office to do further harm. But the text of the second constitutional provision that Luttig quotes suggests that impeachment may serve another purpose — preventing a former official from regaining power and doing future harm.

As scholars Edwin Brown Firmage and R. Collin Mangrum wrote in a 1974 law review article, “the impeachment judgment may extend to both removal from office and disqualification from holding any further office.” But, if the official leaves their current office, that “accomplishes only the first objective.”

A closely related problem is that, if former officials are immune to the impeachment power, someone might resign their office moments before the Senate votes to disqualify them. As law professor Brian C. Kalt wrote in a 2001 article, by strategically timing their resignation, an impeached official “can flout any attempt by Congress to disqualify.”

And there’s also a strong historical argument supporting impeachment of former officials. The American impeachment power, Harvard law professor Laurence Tribe writes in an op-ed responding to Luttig, “derives from the power of the British Parliament.” And the British Parliament had the power to impeach former officials.

Indeed, while the framers were in Philadelphia drafting the Constitution, Parliament was actively engaged in impeachment proceedings against Warren Hastings, a former governor-general of India who left office two years before his impeachment. “The Hastings impeachment,” Tribe notes, “was repeatedly referenced during the Constitutional Convention in Philadelphia.”

So the weight of scholarly evidence points strongly in favor of allowing the Senate to proceed against Trump. That said, the one clear American precedent for an impeachment proceeding against a former official cuts in both directions.

There is no clear American precedent governing whether a former official may be disqualified from office

There is at least one historical example when Congress impeached, but did not convict, a former official. In 1876, the House approved, without objections, articles of impeachment against former Secretary of War William Belknap — Belknap was accused of taking a bribe. Significantly, Belknap had resigned his office while the House was still considering whether to impeach him.

During Belknap’s Senate trial, senators decided to resolve the question of whether a former official is vulnerable to impeachment before they actually voted on whether to convict Belknap, and the Senate voted 37 to 29 that former Secretary Belknap was “amenable to trial by impeachment for acts done as Secretary of War, notwithstanding his resignation of said office before he was impeached.”

It’s worth noting, however, that this 37-to-29 vote was below the two-thirds supermajority requirement necessary to actually convict Belknap, and when the Senate voted on conviction, a critical bloc of senators who believed his impeachment was unconstitutional hewed to that position. Though a majority of the Senate voted to convict the former secretary, no article of impeachment cleared the two-thirds threshold, and several senators who voted to acquit signaled that they did so because they believed that former officials were immune to impeachment.

The Belknap precedent, in other words, provides fodder for both sides of the debate over whether Trump remains vulnerable to impeachment. Supporters of Trump’s impeachment can point to the fact that a majority of the Senate did vote to allow impeachment proceedings to move forward. Meanwhile, opponents of Trump’s impeachment can point to Belknap’s ultimate acquittal, and to the fact that a critical minority of senators believed Belknap’s impeachment to be unlawful.

The Senate can probably do whatever it wants in Trump’s second impeachment trial

In 1989, Congress impeached and convicted Judge Walter Nixon on two counts of giving false testimony to a grand jury (though Judge Nixon shares the same last name as another figure who plays a prominent role in the history of impeachment, this is merely a coincidence). Although the full Senate voted on whether to convict Nixon, the Senate appointed a committee of senators to “receive evidence and take testimony” in Nixon’s impeachment trial. Nixon sued, claiming that, by excluding some senators from some parts of his trial, the full Senate violated its constitutional obligation to “try all impeachments.”

Rather than resolve the question of whether the Senate acted constitutionally when it tried and convicted Nixon, however, the Supreme Court held that the judiciary had no business weighing in on this question in the first place. The Constitution provides that the House has the “sole Power” to impeach an official, and that the Senate has the “sole Power to try all Impeachments.” As the Supreme Court explained in Nixon v. United States (1993), “the commonsense meaning of the word ‘sole’ is that the Senate alone shall have authority to determine whether an individual should be acquitted or convicted.”

It is far from clear whether the present-day Supreme Court, which is both far more conservative and far less inclined to defer to the elected branches than the panel of justices who decided the Nixon case, would extend Nixon’s reasoning to Trump’s second impeachment (though it’s notable that Justice Clarence Thomas, the most conservative member of the current Court, and the only member of the current Court who heard the Nixon case, joined the majority opinion in Nixon). But the implications of Nixon for the second Trump impeachment are fairly obvious.

If “the Senate alone shall have authority to determine whether an individual should be acquitted or convicted,” that strongly suggests that the Senate has the final word on whether a former elected official remains vulnerable to the impeachment power. If the Senate chooses to convict Trump and disqualify him from office, the courts should defer to that judgment under Nixon.

Significantly, the Court’s opinion in Nixon does not mean that legal arguments about whether or not Trump is vulnerable to impeachment are irrelevant. It simply means that it is up to each senator to decide for themselves whether the Constitution permits Trump to be convicted and that the courts should not second-guess those decisions.

And it also means that even if a large bloc of senators argue in bad faith — and for purely partisan reasons — that convicting Trump is unconstitutional, the courts are powerless to overrule that bad-faith conclusion.