Nixon said it about diplomacy, but it's been applied to the Republicans' politics for years now:

In your own mind you have nothing to lose, so you take plenty of chances. It is then you understand, for the first time, that you have the advantage—because your competitors can’t risk what they have already. It’s a piece of cake until you get to the top. You find you can’t stop playing the game the way you’ve always played it, because it is a part of you and you need it as much as an arm and a leg. … So you are lean and mean and resourceful and you continue to walk on the edge of the precipice, because over the years you have become fascinated by how close to the edge you can walk without losing your balance.

In other words: If you act like a mad person, people will have no idea what you might do or how far you might go, and so they will do what you want for fear of what might happen if they don't. Trump has been using this for years. Congressional Republicans have been doing it for decades.

But I say, they only have power if you do fear them. It's time to stop being afraid.