Dear Americans, a lot of people are looking at impeachment through the lens of criminal law, talking about due process, right to confront accusers, and other concepts they only vaguely understand from television cop shows, but are now hearing on Fox News and eagerly parroting without one realising that they usually disdain all those fine points of law as technicalities that they don't think should get in the way of convicting the bad guys.
Their hypocrisy aside, the criminal law lens is an incorrect model for understanding the impeachment and trial process. Criminal law has a thick structure of due process to protect citizens from their government abusing their rights to life, liberty, and property.
But :-
- Their is no liberty right to be president.
- The Constitution gives Congress plenary - unchecked - power over the impeachment and trial process.
Yes, the House can impeach on whatever grounds and with whatever it thinks passes for evidence, and the action cannot be formally unconstitutional (although it could be an attack on the spirit of the constitutional system), and the Senate can conduct an impeachment trial in whatever manner it chooses. That's the nature of plenary power. See Judge Walter Nixon v. United States (1993), the Supreme Court.
The sycophantic Senate Majority Leader, Mitch McConnell, has already announced he'll let the defendant determine the conduct of the trial - which also is an attack on the constitutional system - so there's little chance of Trump being treated in a way any objective observer would call unreasonable. But even if the Democrats ran the Senate and tried him in a very unfair manner, it would not properly be called a violation of due process, nor would there be any appeal or recourse because the Senate trial is a non-justifiable question.