There are boatloads of guests on cable news and talk radio who are sold to viewers as know-it-alls on the subject of impeachment. It is strange since we have only had two presidential impeachments in the history of the country. The fact is there is little true precedent in the area of presidential impeachments upon which to rely. Andrew Johnson was impeached after a horrific and violent civil war fractured the body politic. Bill Clinton was impeached for lying under oath but it was not about a matter of state—it all arose from a private sex affair.

To say we can draw much from these two impeachments and trials in the Senate is an overstatement, as those situations were unique.

Yet, myriad hours of broadcast coverage and column inches in print are spent discussing whether or not the quest of Democrats to force the Senate to hear from witnesses is a fool’s errand. These experts say that even if the Senate subpoenas, say, Mick Mulvaney, the president will simply assert the immunity doctrine or executive privilege, or both, and refuse to allow the witness to testify. Should these predictions prove correct, the Senate will be right where the House was when it could have subpoenaed these witnesses—needing to go to court to force the testimony. And that diversion would mire the entire matter in months and months of court proceedings and appeals, potentially pushing impeachment further into the 2020 election cycle.

Such a scenario, the commonly held wisdom goes, would be fruitless.

There is another path. When it comes to impeachment trials, the Senate not only has the power of subpoena, it also has the power to enforce its subpoenas and it doesn’t need to go to court to seek their enforcement. The Senate can order its sergeant-at-arms to arrest a recalcitrant witness and the chief justice can rule on claims of executive privilege or even immunity. After all, the Constitution mandates that the chief justice “shall preside” when the president is tried in the Senate. “Preside” does not mean “sits there and watches.” It means what it says: The chief justice will make the calls when it comes to witnesses and evidence.

The experts see a world where the Senate would need a court to enforce its subpoenas. But what does that mean? What power does a court have that the Senate lacks? Suppose a court were asked to enforce a Senate subpoena—the end result would be that the court would hold in contempt a witness who refuses to show up to the Senate, it would order the witness to testify, and the remedy if the witness continued to stonewall would be a court assessing fines or throwing the witness in jail.

But the Senate already possesses this same authority on its own. Anyone who reads the Senate impeachment rules can see this in black and white. Here is Rule VI in its entirety:

The Senate shall have power to compel the attendance of witnesses, to enforce obedience to its orders, mandates, writs, precepts, and judgments, to preserve order, and to punish in a summary way contempts of, and disobedience to, its authority, orders, mandates, writs, precepts, or judgments, and to make all lawful orders, rules, and regulations which it may deem essential or conducive to the ends of justice. And the Sergeant at Arms, under the direction of the Senate, may employ such aid and assistance as may be necessary to enforce, execute, and carry into effect the lawful orders, mandates, writs, and precepts of the Senate.

The Senate is fully capable, as half of a co-equal branch of government, to enforce it subpoenas and it can look to its sergeant-at-arms to carry out arrests and imprisonment, if necessary. Since 1821, the Supreme Court has recognized the “inherent” authority of Congress to arrest and detain recalcitrant witnesses. During the Teapot Dome scandal investigation in 1927, the Supreme Court approved of the Senate’s power to have a deputy of the sergeant-at-arms arrest the former attorney general’s brother in Cincinnati when he refused to comply with a Senate subpoena.

In 1973, during the Watergate investigation, Senator Sam Ervin (D-N.C.), chair of the Senate Select Committee on Presidential Campaign Activities, threatened to use the sergeant-at-arms to arrest Alexander Butterfield, then-deputy assistant to President Richard Nixon, when he tried to ignore a Senate subpoena to testify about the existence of the White House taping system.

The backdrop to Senator Ervin’s threat could not have been more dramatic, nor more consequential to the outcome of the scandal, namely, causing the only resignation of a president from office to date.

In June 1973, when then-White House Counsel John Dean testified, he inserted a few sentences into his long opening statement indicating that he thought he might have been taped by President Nixon on the evening of April 15, 1973, in the president’s Executive Office Building suite. (Disclosure: I am friends with, and lecture with Dean.) At the time of the meeting, Dean was breaking with the White House and was perplexed when Nixon got up from his chair and walked to a distant corner of the office to whisper about promising clemency to E. Howard Hunt, one of the handlers of the burglars, if he remained silent about what he knew. Dean thought if the tape existed of that evening and had not been tampered with it would show he was telling the truth about Nixon’s deep involvement with the cover-up. To this day, by the way, that tape has never been located.

That little piece of testimony during a week of testimony by John Dean led Senate investigators to ask potential witnesses if Dean had been taped in that encounter with Nixon. When the investigators put the question to Butterfield, one of the few aides to Nixon who knew of the existence of the vast taping system, he responded, “I am sorry you asked that question” and told them that yes, Nixon taped all his conversations.

This bombshell was related to Senate investigators in a private session on Friday, July 13, 1973. Frantically, the Senate drew up a subpoena to have Butterfield come in to testify on Monday, July 16, knowing that Butterfield, who was then serving as the administrator of the Federal Aviation Administration, was about to fly off to Russia for a meeting with the Soviets. The Senate investigators had real concerns that Nixon might destroy his tapes if given enough advance notice. Securing Butterfield’s immediate appearance was critical.

Sam Ervin dispatched Jim Hamilton, a lawyer on his staff, to serve the subpoena on Butterfield. When Butterfield said he was too busy to attend, Hamilton returned to Ervin, who instructed Hamilton: “Jim, you tell Mr. Butterfield that if he’s not here this afternoon, I will send the Senate sergeant-at-arms out to fetch him and bring him to the hearing.”

Hamilton said that he found Butterfield in a barber’s chair where he delivered the subpoena and Ervin’s message. Later that day, according to Hamilton, Butterfield, “now quite contrite and neatly coiffed,” appeared before the Senate to give his historic testimony.

If the Senate wishes to conduct a fair trial and provide the American people with the witnesses and evidence that heretofore has been hidden by the Trump administration, there is no need to interrupt a Senate trial to go to court to obtain relief. If, for example, Mr. Mulvaney refuses to honor a Senate subpoena, the Senate sergeant-at-arms can “fetch him” and imprison him in the Capitol or some accommodating jail to force him to comply with the subpoena. The chief justice can rule on assertions of privilege or immunity, unless, of course, a majority of the Senate overrules him. The million-dollar question is: are there enough votes?

Should the trial proceed with a handful of patriotic Republican senators voting to allow witnesses—something Majority Leader Mitch McConnell desperately wishes to avoid—the whole nature of the trial changes for the better. And if Chief Justice Roberts presides over the trial knowing that challenges to his rulings won’t strictly be along party lines, President Trump might get the fair trial that he deserves.