It used to be that the working class, broadly speaking - Americans who worked with their hands, who worked in factories, who were not in management - were an interest group, a political interest group. And their main spokespersons were the Democrats. Their platform was the Democratic Party. And that began to change after the 1960s. Not for black or other working class Americans, but for white working class.

The ranks of educated professional swelled as more Americans went to college and more Americans sort of adopted a more cosmopolitan lifestyle and worldview. And as the Democrats were looking for an alternative to the unions who no longer seemed like a large enough base for the party, they found the educated who veered more toward a progressive cultural outlook, who may have had - may have been working in the financial sector, in entertainment, in media, in universities. That became really the rank and file of the Democratic Party over a long period of time.

I think that bias is not a fixed thing. It's not as though some people are biased and others are not. It ebbs and flows. It can be manipulated. It changes according to a person's circumstances.

In a sense, whites who were always sort of the unthinking majority who didn't think of themselves necessarily as one among many interest groups but is simply the dominant group, now as whites become - are close to becoming a minority of Americans, are becoming a political interest group. And that's what Donald Trump is playing to. And it's a really dangerous, volatile game.

I do think Donald Trump would be a catastrophic turn in American history.

Before the nineteen-seventies, most Republicans in Washington accepted the institutions of the welfare state, and most Democrats agreed with the logic of the Cold War. Despite the passions over various issues, government functioned pretty well. Legislators routinely crossed party lines when they voted, and when they drank; filibusters in the Senate were reserved for the biggest bills; think tanks produced independent research, not partisan talking points. The "D." or "R." after a politician's name did not tell you what he thought about everything, or everything you thought about him.

We all have a dark side but we keep it in its place because it's destructive. And Donald Trump has said, no, no, bring it out because that's the energy we need in order to reverse all these horrible things that have been happening in America.