Alan Dershowitz has said that Kavanaugh can only be impeached for acts conducted while on the Supreme Court, not prior acts to that position (same for Trump - only for acts as President, not prior). Then again, the Dems don’t care about the law and impeachment is ‘political’ so I imagine they’ll try to go after him on whatever grounds they want. It ‘should’ be a major waste of time/energy and as you said, I don’t think either will be removed from office. If the Dems go after impeachment charges, they will continue to demonstrate that they are the equivalent of turd-throwing baboons.
I have no doubt that the Founding Fathers and various court rulings have confirmed Professor Dershowitiz's position.I also think that you're entirely correct regarding the Rat Party's utter contempt for the rule of law.
I believe that it's that contempt that will cause them to manufacture grounds for impeachment...with Kavanaugh *and* Trump.