Arresting and sending all of Congress to Gitmo will immediately collapse the stock market. It would be the biggest/fastest drop in history. Probably drop 95% overnight.
There would be mass riots and civil unrest like never seen before, power blackouts, food shortages, looting, etc.
If it happens, its going to look like Armageddon for a while so if you really believe he's going to arrest nearly the entire government be prepared and stock up on food/water.
I doubt that. You would have the NG, military, and us to keep order. TBH this is the best case scenario versus a new revolutionary war.
But it has to be done no matter what. We can't live knowing that Ruby Freeman decided the election with her boss and her cronies. Democracy isn't five people at 2AM stuffing ballots.