They can send him to jail until he agrees to satisfy their demands, just like a contempt of court. Worked for the “Hollywood 10”, why would Holder be any different?
Because Holder is one of Holder’s People.
The House of Commons had that power, when the Constitution was adopted, but the House of Representatives has not been that high handed. It asks the United States Attorney for the District of Columbia to bring a contempt proceeding in the United States District Court for the District of Columbia.
Of course the US Attorney works for... Attorney General Eric Holder.