You are not innocent until proven guilty; you are presumed innocent until proven guilty beyond a reasonable doubt. You are guilty, or you are innocent, from the beginning; only, we admit uncertainty in the presence of reasonable doubt, which evidence and argument need erode to prove guilt.

I'm afraid it's not quite so absolute. Consider a murder case in which the defendant admits to killing a person, but pleads self defense. It is certainly a fact that he killed the person, but whether it was self defense or not (i.e., whether he is guilty or innocent) depends entirely on the interpretation of the law and the events that occurred. Absent a finding of law, his guilt or innocence simply can't be established. If we hold the presumption of innocence and the absolute idea that he either is guilty or not, then we would have to conclude he is innocent, rather than taking the more rational view that we simply don't know.

Impeachment isn't a criminal trial.

While this is true, there is no dispositive ruling on the totality of criminal procedural law as it applies to impeachment. The 1936 impeachment of Judge Ritter was the first point a defendant in an impeachment trial appealed to a court to assert his procedural/constitutional rights had been denied by the Senate. It is clear there are procedural requirements the Senate must honor, but the full extent is not clearly defined. For a decent review of the area as it stood in 1993, prior to the Clinton trial, see [0].

0 —> https://digitalcommons.law.umaryland.edu/cgi/viewcontent.cgi...