The most important thing to me, in terms of thinking about the issue of impeachment, is to recognize that the Constitution does place a value on continuity. We don't want to have a situation where you make a single error, and you're exposed to an impeachment proceeding.
What you find is that the U.S. Supreme Court very seldom if ever marches very far from the conventional thinking of contemporary society. They pay attention and are infected by mainstream thinking of what's moral and what's right and what's just.