How Impeachment Trials Work
The Constitution says relatively little about how presidential impeachment trials go. Senators must take an oath before sitting for a trial, the chief justice of the United States presides, and a conviction requires “two thirds of the Members present.” The Constitution also names two punishments upon conviction. The first punishment mentioned in the Constitution, “removal from Office,” would presumably follow immediately upon a president’s conviction, as happens when an impeached judge is convicted. The second named punishment is “disqualification to hold and enjoy any Office of honor, Trust or Profit under the United States.” As a matter of historical practice, the Senate has since 1862 treated the punishment of disqualification from future office as optional and subject to a simple majority vote. If Donald J. Trump is removed from office and the Senate subsequently votes to disqualify him, then he presumably* cannot run again in 2020.
To understand what will happen in the days and weeks ahead, keep in mind two things. First, there are rules and precedents, based on historical impeachment trials of judges and presidents, to guide what the Senate will do. Although the rules and precedents don’t address every possible contingency that might arise, they will lend some shape to the proceedings. Second, though, the Senate can amend or even override the rules for the purposes of Trump’s impeachment trial.
The 26 Senate rules regarding impeachment trials, tucked away in the overall rules of the Senate, are largely based on the rules first proposed in February 1868 for the impeachment trial of President Andrew Johnson. Under the rules, once the Speaker of the House names the impeachment “managers”—that is, the subset of representatives who will participate in the Senate trial as de facto prosecutors—the House is to notify the Senate. The Senate, in turn, notifies the House that it is ready to receive the articles of impeachment. The impeachment managers then walk across the Capitol, from the House chamber to the Senate chamber, and are introduced to the Senate. A moment later, the sergeant-at-arms makes an arcane proclamation on the Senate floor commanding everyone present “to keep silence, on pain of imprisonment.” The managers, standing, then read aloud the articles of impeachment passed by the House.
Once that happens, Senate rules provide that the trial must start no later than 1 p.m. the next day and continue each day, except for Sundays, until the trial concludes.
Had Speaker Pelosi named the impeachment managers along with the December 18 vote to impeach Donald Trump and immediately transmitted the articles of impeachment, the trial could have kept the Senate in session six days a week over the holidays. That would have been unpalatable for everyone involved, including members of the American public who need a break from watching hours of extravagant congressional rhetoric and back-and-forth sniping over Trump’s misconduct.
Let’s turn now to four details about impeachment trials that sometimes create confusion.
1. Can the Senate avoid holding a trial? And does the Senate need to consider all the articles of impeachment brought by the House?
Although it is sometimes argued that the Constitution gives the Senate no option but to hold a trial after the House impeaches a president, the requirement is nowhere in the Constitution or even in the Senate rules. Theoretically, a majority of senators could vote to dismiss the impeachment articles prior to trial on the rationale that they are frivolous or even unconstitutional, as some Republicans have argued.
And once a trial has begun, a majority of senators could vote to end it at any time, even without voting on the articles of impeachment. During the trial of President Johnson in 1868, the Senate voted on only three of the eleven articles of impeachment—the three that seemed likeliest to result in a conviction. When those failed to reach the two-thirds threshold for removal, the impeachment trial was adjourned.
2. How much authority does the chief justice wield?
Whereas the House impeachment proceedings lacked a neutral umpire, the chief justice will keep order throughout the trial process. The Senate rules specify that the chief justice “shall direct all the forms of proceedings” and “rule on all questions of evidence” during the Senate trial, although any Senator can call for a vote to overrule him, as happened during the Johnson trial. He is sworn in, and then swears in the senators, who respond one by one and sign an oath book. (You can see video of this procedure from the 1999 Clinton trial here.)
Beyond that, the chief justice’s role is ill defined. If Chief Justice John Roberts follows the example set by Chief Justice William Rehnquist during the Clinton trial, his role could be mostly ceremonial, deferring to the advice of the Senate parliamentarian and to what he takes to be the wishes of the Senate majority. But he has discretion to do more, including ruling on a hypothetical motion to dismiss the articles of impeachment or a motion to call controversial witnesses to testify. His rulings would then be subject to reversal by a majority Senate vote.
3. During the Senate trial, are the senators to act as “jurors”?
Although the Senate proceedings are a trial, the participating senators do not strictly function as jurors, as they have the ability to change the rules of the trial and override decisions by the presiding officer, the chief justice. This point was clarified during an odd moment of the 1999 Clinton trial, when Senator Tom Harkin (D-Iowa) interrupted a presentation from one of the House managers to “object to the use . . . of the word ‘juror’” to describe senators, and to highlight the differences between regular jurors and senators sitting in an impeachment trial.
Chief Justice Rehnquist agreed: “The senator from Iowa’s view is well taken. The Senate is not a jury, it is a court in this case. And therefore counsel should refrain from referring to senators as ‘jurors.’”
4. Will witnesses participate in the Senate trial?
There has been much coverage of Senate Minority Leader Chuck Schumer’s (D-N.Y.) request that the trial include actual witnesses, and that the witness list be expanded beyond those who testified in the House proceedings. Specifically, Schumer wants to hear from acting White House chief of staff Mick Mulvaney, who admitted publicly to a quid pro quo; former National Security Advisor John Bolton, who according to witnesses angrily refused to participate in the “drug deal” that led to Trump’s impeachment; Robert Blair, a senior advisor to Mulvaney; and Office of Management and Budget (OMB) official Michael Duffey, who may be able to explain Trump’s rationale for freezing the $391 million in military aid to Ukraine a scant 91 minutes after his infamous call with Ukrainian President Zelensky in which he asked for the “favor” of investigating the Bidens.
Democrats are rightfully fielding criticism for failing to move the federal courts to compel pivotal testimony and documents in the House impeachment inquiry. The latest tidbit about the timing of the OMB directive emerged from a private party’s Freedom of Information Act request—not a House demand. A federal judge granted a preliminary injunction to make the OMB documents public, underscoring the ability of courts to move quickly if asked, as well as Democrats’ failure to push through the White House stonewalling.
Of course, Senate Democrats cannot control their House counterparts, and just because House Democrats snoozed on their obligation to enforce Congress’s subpoena prerogative does not mean that Americans should be deprived of the full facts in the Senate. McConnell’s cynical rejection of Schumer’s request hurts the American public and the rule of law—but that has hardly stopped him before.
What, if anything, can Senate Democrats do under the rules to force McConnell’s hand?
The rules allow the Senate to compel witnesses. They also authorize the Senate to punish people who defy subpoenas by holding them in contempt, a power that the Senate sergeant-at-arms can execute.
Currently, there are 53 Republicans in the Senate and 47 Democrats. If Schumer wishes to issue a subpoena to Mulvaney, for example, it would take four agreeable Republicans to make it stick. Already, Alaska senator Lisa Murkowski has said she is “disturbed” by McConnell’s pledge of “total coordination” with the White House. If moderate senators like Mitt Romney and Susan Collins were to join efforts to hold a legitimate trial based on actual facts, Chief Justice Roberts might act to break the impasse. He would be within his authority as presiding officer to rule on the admission of evidence to determine if it is relevant, material, or redundant—and could hardly conclude in good faith that Mulvaney’s testimony is not relevant to the first article of impeachment charging an abuse of office.
If witnesses do end up testifying, the rules would prohibit senators, House managers, and counsel for the president from examining them directly. One person from each side is permitted to question witnesses, and any questions for witnesses that the senators might have must be submitted in writing to the chief justice. No “colloquy” is allowed among the senators. The rules also put time limits on the length of oral arguments about preliminary questions, including a motion to close the proceedings to the public. This suggests that we are unlikely to see the grandstanding, shouting, malingering, and name-calling that colored the proceedings in the House.
But alas, even Chief Justice Roberts cannot stop presidential witness-tampering on Twitter. For that, the Constitution gives Congress the “sole” power to check the presidency through impeachment and removal.
* Editor’s note: Since this piece was first posted, we inserted the word “presumably” here to acknowledge that there is some academic dispute, and no historical precedent, regarding whether the Senate’s disqualification power can apply to presidents.