Anyone expecting senators to behave like jurors in President Donald Trump’s impeachment trial is bound to be disappointed. In ordinary criminal trials, we disqualify jurors if they know the defendant, the witnesses, or even the latest news. If we applied those standards to senators, we'd have to disqualify the entire Senate.

Fortunately, it is possible for senators to be both political and fair. Today’s senators would do well to study the example set by their predecessors in trying President Bill Clinton.

Clinton’s 1999 trial involved a politically divided Senate of 45 Democrats and 55 Republicans. Nevertheless, by a vote of 100 to 0, the Senate followed procedures outlined in its 1986 resolution entitled "Procedures and Guidelines for Impeachment Trials." Trent Lott, the majority leader at the time and a fierce Republican partisan, did not stand in the way of this unanimous agreement. In the end, 10 Republicans voted to acquit President Clinton on one article, five on the other.

Among other matters, the 1986 rules provided that "the Senate shall have power to compel the attendance of witnesses." When disagreement broke out about whether to call witnesses, the senators deliberated in private, and then publicly voted to depose witnesses. The senators heard videotaped deposition testimony for three days from witnesses.

The 1986 rules are still in force. Yet Senate Majority Leader Mitch McConnell has declared his intent to ignore them and to run the trial according to whatever procedures the White House wants. Apparently, McConnell sees no conflict between swearing an oath to do justice according to law and then confessing that "Everything I do during this, I'm coordinating with the White House counsel."

Unless something changes, politics will displace law in any Trump impeachment trial. To her credit but also to her peril, House Speaker Nancy Pelosi has departed from the example the House set in 1998, when members immediately walked over the articles of impeachment to the Senate. Instead, the speaker has announced that transmission of these articles will be delayed until the chambers can agree on fair trial procedures.

Some accuse the speaker of her own political maneuvering to deny, or at least to delay, the president’s right to answer his accusers. Others defend her as having no choice but to use whatever leverage she possesses to ensure that the Senate conducts a trial, and not a farce.

So far, Pelosi has said only that she will delay transmitting the impeachment articles, as opposed to saying she might never send them. 

If the speaker persists and refuses to deliver the impeachment articles to the Senate, some will say she is the one violating the Constitution. While the Constitution contains no explicit provisions concerning the time frame for transmitting articles, or even compelling delivery, you could argue that it implicitly assumes a Senate trial will follow impeachment in a timely manner.

In ordinary circumstances, this argument might be persuasive. However, these are not ordinary times. Left unstopped, McConnell by his own words stands ready to violate the Constitution’s core commitment to fair trials under the rule of law. The Constitution does not require the speaker to sit back and watch the Senate disobey the Constitution. And McConnell cannot invoke the importance of holding a Senate trial while refusing to hold anything resembling an open trial.

We can walk back from this constitutional precipice. If senators in the Clinton impeachment trial could put aside their partisan divides and unanimously agree on fair trial procedures, then today’s senators should be able to do the same. 

An early draft of the Constitution proposed holding impeachment trials before the Supreme Court. But Alexander Hamilton thought it would be a mistake to take all politics out of the impeachment trial. Instead, he counted on the Senate’s ability to distinguish between the petty politics of self-interest and the permanent political interests of the people in living under the rule of law. The very gravity of impeachment, Hamilton thought, would turn politicians, sometimes drunk on power, stone sober.

Before it is too late, we should all raise a glass to constitutional sobriety.

Jeffrey Abramson is the author of "We, the Jury: The Jury System and the Ideal of Democracy."