I support Trump and believe this impeachment is a load of crap....
But i also believe that it is up to Congress, not the Supreme Court, to decide what is a high crime or misdemeanor. I would point out that if you think that is for the Supreme Court to decide, that would leave impeachment of Supreme Court justices to their own discretion as well, which is an absurd result. I cannot believe the Framers would have given to the unelected third branch - appointed for life, no less -- the power to veto any attempt to remove either them or the President.
It may sound good to some that the Supremes could stop an unjust impeachment of Trump. But if you give them that power, then you also give to that Court the power to stop a perfectly just impeachment of a future President AOC.