George Bernard Shaw said that “only lawyers and mental defectives are automatically exempt for jury duty.” Unless, of course, it is the Senate, where you can be both of those and still sit as a required jury member.

The controversial role of senators in an impeachment trial is back in the news, as various House members challenged the right of some Senate Republicans to take the oath to promise impartial justice after defending President Trump. Less than 24 hours after being named one of the seven House impeachment managers, Representative Val Demings called for the recusal of Senate Majority Leader Mitch McConnell for being biased. Her proposal is as unfounded as it is ironic, since she called for the removal of Trump more than a year ago, which was before the Ukrainian phone call.

In reality, the rules of the impeachment trial are set by Senate majority vote. Moreover, the White House has not had its way on its two principal demands for summary dismissal or witness testimony. But the premise of much of this discussion is that the coordination and comments made by Republicans violate both their oaths and Senate tradition. This view was amplified by University of North Carolina law professor Michael Gerhardt, who testified as a witness with me in the House impeachment inquiry.

Poppy Harlow asked him “how normal or abnormal” it is for the Senate majority leader to work in such “lockstep” with the White House on a trial. Gerhardt declared, “It is extremely unusual. This is the first time in history when the president was coordinating with a big bloc of people from his own party in the Senate.” He continued, “Bill Clinton was not coordinating with the Democrats. In fact, they kept a fair distance between themselves. This is the first time we have seen this kind of coordination.” Despite my respect for Gerhardt, history does not actually bear out that statement.

Little is known of the coordination during the impeachment of President Johnson in 1868. However, the Senate was overwhelmingly Republican and opposed to Johnson, who was affiliated with Democrats and later the National Union Party. The very idea of the majority coordinating with him on the trial would have been absurd. With President Nixon, Democrats controlled both the House and the Senate. Moreover, no trial was being actively planned and Nixon chose to resign before he was impeached.

That leaves the trial of President Clinton. Again, there was no coordination with former Majority Leader Trent Lott because Republicans controlled the Senate. Yet Democrats Harry Reid and Tom Daschle did coordinate with the White House, as reported in the media. The book “The Breach” details the close workings between the Senate and the White House staff. Clinton also spoke with senators. Howard Kurtz of the Washington Post back then had reported on a “Democratic senator who was consulting regularly with President Clinton” on the trial, and an Associated Press story had reported that senators and the White House were finalizing the strategy for the trial.

Some like Daschle were uncomfortable. He said Clinton was “leaning very heavily” on Senator Ted Kennedy and noted that “these are the 35 names, things he wanted, and a strategy he wanted to pursue.” Daschle tried to maintain some distance but admitted that he and Kennedy pursued the same approach on the details for the trial. Now, however, the objections ignore the close coordination between House Democrats, who act as the prosecutors, and Senate Democrats, who act as the jurors. As with the White House discussions, there is nothing unusual in such coordination.

The same is true with pretrial commentary. Senators should refrain from stating conclusions about the evidence before trial, but they were never expected to stop being politicians. Unfortunately, the rule of restraint is observed in the breach by many. Minority Leader Charles Schumer is a rather curious ethics oracle in denouncing his Republican counterparts for expressing support for Trump. History shows that Schumer ran for the Senate based on his promise made before trial to vote to acquit Clinton.

When it comes to Senate trials, bias is in the eye of the beholder. While the media has focused on comments by Republicans, many Democrats have been as vocal in declaring Trump guilty as their counterparts have been in declaring him innocent. Senator Elizabeth Warren campaigned on his guilt and, when asked if she intends to vote to convict Trump, vowed clearly, “Of course I will.” Senator Kamala Harris declared, “As a former prosecutor, I know a confession when I see it. He did it in plain sight.”

Senator Chris Coons warned the nation about the dangers of failing to convict and remove Trump. Senator Amy Klobuchar not only declared Trump guilty but described the allegations against him as nothing less than a global Watergate. Senator Richard Blumenthal wrote that Trump is guilty ahead of the House impeachment vote. Senator Chris Murphy said Trump was “preying on a vulnerable foreign nation” for “personal political benefit,” while Senator Jack Reed accused Trump of a shakedown. Senator Brian Schatz claimed that supporting Trump would “swallow the republic.”

Senator Edward Markey said our “very democracy” is at stake here and “there is no place” for Trump to hide. Senator Sherrod Brown admitted he is “disappointed in my colleagues, this see no evil, hear no evil attitude.” Apparently, all the “see only evil, hear only evil” comments of his fellow Democrats are not a problem. House manager Adam Schiff called the pretrial comments a disgrace, but of course only those of Republicans.

Senators are not asked to sequester themselves or to take a vow of silence before a trial. The Framers had no delusions about the jurors designated in the Constitution. They knew that these trials demand an unnatural act to set politics aside in the jury deliberations. Politicians were no less biased or more circumspect in the 18th century than they are in the 21st century. Indeed, politicians are one of the few elements of government that have changed little over time in terms of their predictability or predilections.

While unfortunate, comments on the merits of impeachment are neither unprecedented nor unexpected from politicians. What is expected is that senators ultimately will vote their conscience. Past impeachments have shown that senators can indeed transcend petty political instincts when their names are called, not just by the clerk but by history, and rightly so.

Jonathan Turley is the Shapiro Professor of Public Interest Law for George Washington University and served as the last lead counsel during a Senate impeachment trial. He testified as a witness expert in the House Judiciary Committee hearing during the impeachment inquiry of President Trump.