Fareed Zakaria on why Republican senators won’t challenge Trump.

In your conversations with people in the Senate, what's going on there? Why is there no push back? You have no idea how much these people want to be senators. For many of them, this is what their whole life's ambition has been. If Lindsey Graham got up in the morning and wasn't a senator, he wouldn't know who he was. His entire life is being a senator. This is a kind of design flaw in the American political system. James Madison when he wrote the Constitution, his assumption in the checks and balances system was the Senate and the House as institutions will always jealously guard their power. But he didn't realize that what was going to happen was you're going to get these things called political parties. And the key to Trump's success is that he dominates the Republican party like no president I have ever seen dominate. It really is almost like a cult, his base. And so that's the basic problem.