James Madison, sometimes called the "Father" of our Constitution, wrote on October 15, 1788 (thirteen months into ratification), "The great desiderata on a Court of Impeachment are 1. Impartiality and 2. Respectability" (credibility). In order for the Senate to give an impartial and credible trial to President Trump, several key changes must be made in the Senate rules. If these changes are not made during the early stages of the trial, it will be (as Samuel Spencer predicted on July 28, 1788, in commenting on Hamilton's attempt to justify the assignment of the trial power to the Senate), "very little more than a farce". It will be neither impartial nor credible, nor will it conform to the principles and dictates of the Constitution. This constitutional defect will make both the Senate Impeachment Rules and the trial subject to judicial review.
The most critical rule change needed is the revision of Rule VII of the Senate Impeachment Rules. This rule strips the Chief Justice of his constitutional power to make binding rulings. By doing so it strips the court of its reason for existing: its potential for rendering impartial justice. The fact that the Framers made the judicial nature of impeachment trials explicit by using the word "preside" makes any other meaning nonsensical
During the first few days of the Convention, Hamilton submitted a proposal including an impeachment court including the judiciary. Madison was a consistent champion of this separation of powers. He said, six days before the Convention finished its work, that "He would prefer the Supreme Court for the trial of impeachments, or rather a Tribunal of which that should form a part." However, Hamilton, two days before the Convention ended, reversed himself with a successful proposal giving the Senate the impeachment-trial power. He defended this reversal in Federalist 65: " To a certain extent, the benefits of that union will be obtained from making the chief justice of the Supreme Court the president of the court of impeachments."