In light of all this — against all my instincts — I am sinking into cynicism. If the best of the Republican Party is willing to make shallow, shoddy excuses for an unfit president, then the path ahead is disturbingly clear. The details of the case for impeachment, it seems, will not finally matter. Fearing the revolt of their base — and the retribution of an emotionally unstable president — Senate Republicans (with one admirable exception, Utah’s Mitt Romney) have already chosen their final position: acquittal. And whatever is revealed in the course of the investigation — no matter how vomitous — will fall just short of an impeachable offense. The goal posts will move and move until they are in the next county. And tolerance for corruption in high places will continue to grow.

In an ideal world, senators would turn to political philosopher John Rawls for guidance. He proposed that judgments about justice should be conducted behind a “veil of ignorance” — as though we did not know the station in society we would inhabit. On this theory, Republican senators should ask: If I did not know whether the president were a Republican or a Democrat, would his or her willingness to compromise national security for selfish political reasons demonstrate unfitness and justify conviction?

But almost no Republican senators, as far as I can tell, are operating behind the veil. Their verdict is predetermined by partisanship. And I am cynical enough to believe that very few Democrats — if the situation were exactly reversed and a Democratic president were being judged for similar actions — would heroically resist their political incentives.