E.J. Dionne:

In the book, we quote the great line from John F. Kennedy in his inaugural address, 'he who foolishly rides to power on the back of the tiger ends up inside,' and I think the Republican Party was willing to play — the establishment of the Republican Party was willing to play with a lot of divisive themes over a long period of time, and they assumed that they could keep this radicalism under control. They could get votes out of it but eventually they would end up on top.

So, for example, when Donald Trump was being a birther, was charging falsely that Barack Obama had not really been born in the United States and was, therefore, ineligible to be president, a lot of Republicans said, oh, we don't believe that, but very few just denounced it, were willing to denounce it. John Boehner we quote in the book who certainly was not a birther but he said, well, people are entitled to their own opinion.

No. When people did that sort of thing, when there was this very harsh anti-immigration sentiment, the Republican leadership needed to speak up and they didn't. And I think you saw, also as we talk about in the book, that the first inkling you got of what trouble the establishment was in was when Eric Cantor lost a primary that he never expected to lose, and here is someone who welcomed the Tea Party who said this is all great stuff, and then the tea party beat him in the primary. So, the Republicans really laid the groundwork for what they got here.