At the outset of the Senate impeachment trial of President Donald Trump Thursday, Supreme Court Justice John Roberts, mandated by the Constitution, required each Senator to swear an oath to do impartial justice according to the Constitution and the laws of the United States.
Article I, section 3, clause 6 of the Constitution provides: “The Senate shall have the sole Power to try all Impeachments. When sitting for that Purpose, they shall be on Oath or Affirmation. When the President of the United States is tried, the Chief Justice shall preside: And no Person shall be convicted without the Concurrence of two thirds of the Members present.”
The oath provides: “I solemnly swear (or affirm, as the case may be) that in all things appertaining to the trial of the impeachment of [Donald John Trump], now pending, I will do impartial justice according to the Constitution and laws: so help me God.”
This is especially important in this case where at least two Senators, Majority Leader Mitch McConnell and Lindsey Graham, already have declared in essence that they have no intention of honoring the oath.
(McConnell said on Fox News: “Everything I do during this, I’m coordinating with White House counsel. There will be no difference between the president’s position and our position as to how to handle this to the extent that we can.” And Graham has stated: “I am trying to give a pretty clear signal I have made up my mind. I’m not trying to pretend to be a fair juror here.”)