Senators must honor their oaths at Trump impeachment trial, just like I did for Clinton

To all who serve in the world’s greatest deliberative body and believe it must live up to that description: Don't let history’s verdict be a question mark or an asterisk.

The framers of the Constitution purposely and thoughtfully put the solemn responsibility of impeachment trials in the hands of the Senate, where they envisioned people of courage and conviction weighing facts and evidence.

I worry that the Senate is falling short of its responsibility. So far, the Senate has declined to seek further evidence and papers, on a party line vote. Indeed, the impeachment trial has dawned with a series of party line votes, as was the case in the House. To be clear, the Senate is not the House. It’s supposed to be an institution where — particularly on issues of process, if not ideology — common ground is identified through careful compromise.

It was familiar to hear Chief Justice John Roberts invoke the words “world’s greatest deliberative body” as an admonition to the House members presenting the case and the legal team defending President Donald Trump. But it should be just as much a warning to the senators themselves: Senators have the chance to affirm what the framers envisioned and — even if it doesn’t change anyone’s mind — secure all relevant evidence and make an informed decision to defend the Constitution and the republic.

Senate right to oversight is on trial

If they were here today, I can assure you that the leaders I served with — whether Republican leader Bob Dole or Democratic leader Robert Byrd — would understand that when the Senate surrenders its oversight powers to a runaway executive on a partisan basis, the Senate’s own prerogatives are on trial.

During the 1999 impeachment trial of President Bill Clinton, the Senate carefully weighed all the evidence sent from the House and gathered some of its own. This included 90,000 pages of documents Clinton had produced for special counsel Kenneth Starr's investigation, and testimony from three witnesses the Senate subpoenaed for additional questioning. What senators requested, they received.

Twenty-one years later, the short House investigation and the White House refusal to produce documents or comply with subpoenas make the Senate role especially important. Senators must hear from any witness and see any document that common sense and due diligence suggest would help shape an informed verdict.

In a presidential impeachment, senators are not jurors but finders of fact and then judges of whether those facts are of sufficient gravity to remove the president from office. In reaching that judgment, senators may consider not only the case presented by the House prosecutors but any other facts they deem relevant.

An impeachment trial is not a criminal proceeding. In fact, Alexander Hamilton, in the Federalist Papers, labeled impeachment a political process, a description that certainly fits this process — so far — to a T. But In a larger sense, there is a jury: the American people. The people must feel that the process was fair, relevant evidence presented and the verdict just in order that it be widely accepted.

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In any trial, the decision-makers need to hear from witnesses and see the evidence in order to reach the best possible verdict. And they can't hear witnesses who have been blocked or read evidence that has been hidden.

The Founding Fathers established this process to hold to account even those in the highest offices of the land. The rule of law depends on an even-handed weighing of the facts of the matter and a fair adjudication of what those facts merit. But it only works if you have all the facts. The Senate must not conclude this process without considering all the relevant facts.

Without impeachment, 'divine right'

The founding generation forged for us a system of self-government designed to cast off the burdensome weight of the old world’s anachronistic theory of the “Divine Right of Kings.” Here in America, the people rule, and so should the facts.

Impeachment is about the rule of law in a political arena. A full understanding of the facts should be senators' top concern, with partisanship a distant second.

I know firsthand the challenge of wrestling with the complex issues involved in a Senate impeachment trial. In 1999, I found President Clinton not guilty of perjury. But I concluded he was guilty of obstruction of justice and ultimately voted to remove the president from the office he had twice won in national elections. I stand by those votes to this day.

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I said to my fellow senators then what I say now: “I cannot will to my children and grandchildren the proposition that a president stands above the law … simply because both his polls and the Dow Jones index are high.” Further, I said, “The republic will not be weakened if we convict. The policies of the presidency will not change. The administration will not change.” The Founders knew what they were doing.

The Senate needs to consider all the relevant evidence, facts and witnesses to reach a just and acceptable outcome. The trial should be a model to countries everywhere for how America delivers justice, not a partisan food fight or a kangaroo court. To those who will soon be casting a verdict, history will forever remember: You swore an oath to deliver impartial justice in this matter.

Now, honor that oath.

Slade Gorton served three terms in the United States Senate as a Republican from the state of Washington.

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This article originally appeared on USA TODAY: I weighed all impeachment evidence in 1999 and voted to remove Clinton