[wan23]

That's not how it works - in the case of impeachment the Senate holds a trial, and they are allowed to use their own definitions of treason, bribery, etc. The Supreme Court is in charge of what the regular courts do and can make rulings that bind them, but they can't bind Congress in the same way. After all, the justices of the supreme court are also subject to the impeachment process like the President is and it'd be weird if they could make rules about how that works.