Each Member of Congress takes this oath on their first day of work:
"I do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I take this obligation freely, without any mental reservation or purpose of evasion; and that I will well and faithfully discharge the duties of the office on which I am about to enter: So help me God."
When they signed Grover Norquist's pledge, they violated this oath. Therefore, they should be impeached because they refuse to discharge their duties mandated by the Constitution. Grover Norquist is an enemy of the United States of America, he wants to bring down the government of this nation. Charge him w/treason to