Strip her of all her major committee assignments, cosigning her to sitting on more irrelevant committees. If she repeats remarks such as calling for Pelosi's execution or other crazy things she has said over the years, move to expel.
The GOP could expel her from the Caucus. She could respond by collecting a paycheck for doing nothing for 2 years, but that might be a good thing.
For those of you that view MTG as an aberration, remember that her election is very much in the spirit of democracy. There is a reason the Founders limited popular election of Federal officials solely to the House of Representatives; they believed that "the people" would elect all sorts of MTGs. It's one of a number of reasons of why the Founders opted for a bi-cameral legislature.
It's also a reason why we are not a "democracy", but a REPUBLIC. Our Republic has, to be sure, democratic features, but we are not a "democracy". The "Guaranty Clause" guarantees that each state will have a "republican form of government", and not a "democratic form of government". The older I get the more appreciative of this principle I become.
The words democracy and republic are not mutually exclusive. America was founded and remains a democratic republic
