If Amar is right, Congress could seat Vladimir Putin (in suitable disguise of course, so as to fool the people), and there is no remedy, no check.”
This is a true statement. I think the only check in this fact case is that the Reps are sworn to uphold the Constitution. (I know that the oath of office idea is quaint in 2015...).
On high crimes and misdemeanors, that is the standard for impeachment. It’s the...as it were..the natural born citizen analog to the impeachment clause. Over the years, people have tried to give it some sort of binding content. (Perhaps, also analogously, to the advice and consent of the Senate...but based upon....what?). This push for content has never really borne much fruit. It is basically what the House says it is, and their decision is unreviewable. It just goes to trial (and you are of course correct that the Senate’s sentences are prescribed).
I need to review the text of the Constitution itself. I am not sure one way or the other as to whether it makes Congress the sole judge. You think that it clearly doesn’t, and Amar thinks that it does....and you have made good points here. So I’ll try to get to that asap and wade back in. Thanks...
Just in case you want to read Amar's foil on the reviewability question.