In Federalist number 65, Alexander Hamilton tried to justify the decision to give impeachment trials to the Senate by insisting that the Supreme Court would have lacked the “fortitude” to remove the president, and that the justices, being few in number, would not possess the “credit and authority” needed to remove a president. He then added Morris’s old argument that the Supreme Court might have to judge a criminal trial of the president after he was removed from office. Hamilton dealt with a version of Madison’s idea of a Supreme Court-led tribunal by repeating the same concern; and he concluded that having the Chief Justice preside over the Senate trial was a “prudent mean” between the two options.
Ultimately, the framers trusted the Senators to have legitimacy and to act in accordance with their oaths. And it’s fair to say that through most of constitutional history, the Senate has done an adequate job of trying impeachments.
Today’s partisanship threatens that legacy. Arguably, a trial in which all witnesses are excluded is not a trial at all. If the Senate can’t produce a trial that makes Americans believe it possesses the “credit and authority” to try the president, maybe it’s time to start thinking about a new constitutional solution.