The normal court response is to issue an arrest warrant for a subpoena violation. Will that happen to him?
Congress is not your normal court, and doesn’t have the same arrest powers as a real Judge in a real court, as far as I know.
I read that the Sergeant at Arms has arrest powers, and Congress has some sort of holding cell, but that this hasn’t been used for 80 years.
Holder gave Congress the finger, and they didn’t do a thing.