David Gergen: “Any one of four Democrats could win the White House next year, more easily than you can see a Republican winning.”

I think the turning point that came were the midterm elections. The fever broke with those midterm elections. And what we've seen since then is a steady decline in Trump's credibility and in his position with the American people, and a…

I think we're in an unsustainable path. It's compared to being in a car on the edge of a cliff, and middle of the night with it with a rainy and no headlights.

If he comes out and throws cold water on this, then I don't think it goes anywhere.

Maintaining the status quo with regard to the filibuster is unacceptable for him.