National Congress/House may hold the Judge in contempt, etc., but they can't do anything about his verdict. His verdict is a state matter.
Unless a Federal court intervenes or possibly the state Governor, little else can be done. The state Legislature can possibly intervene and overrule the judge.
The Governor can intervene? Didn't know that...I'm not up to speed on constitutional law, at all. What are the Governor's options and are they feasible?
Federal Marshalls can arrest the judge if he is found in contempt by the House.
As of the moment the subpoena was issued, I believe that Terri Schiavo became a Federal witness. Judge Greer has ordered action that will lead to the imminent death of this federal witness. My understanding is that that all efforts must be taken to keep the witness alive and unharmed until such time as she is dismissed as a witness or her situation is otherwise legally altered.
What I don't understand is why this witness is not at this moment in the custody of federal marshals charged with keeping her from harm. I also don't understand why federal marshals have not arrested this S.O.B. Greer for ordering that this witness be put to death. I feel certain that he will suffer some sanctions and political consequences for telling the HofR to go suck it up but that's for later