"This one is not based on a system; it's just my gut. They don't want Trump as president, because they can't control him. He's unpredictable. They'd love to have Pence - an absolutely down-the-line, conservative, controllable Republican," Lichtman told The Post. "And I'm quite certain Trump will give someone grounds for impeachment, either by doing something that endangers national security or because it helps his pocketbook."