“Hillary Clinton’s loss had an exponential effect,” says Robert Boorstin, who was a Clinton White House speechwriter and a pollster for Al Gore in 2000. “Because it changed the rules of the primary game—because people thought it was rigged against Bernie Sanders, and there is some evidence that it was at least heavily weighted in her favor. But it’s also changed what’s ideologically acceptable.” (In fact, it seems beyond doubt that Hillary Clinton’s dominance of party processes and elders gave her a leg up in 2016.)
Ben Rhodes, the former Obama speechwriter and deputy national security adviser, told me that the extent to which Trump has scrambled the country’s political culture has had a powerful impact on the Democrats. “One is the idea that politicians were mandated to play within an established set of lines, that were set by some perceived conventional wisdom, kind of goes out the window—Trump has tossed out a sense of ideological constraint,” Rhodes said. “And the other is the extent to which Trump has mobilized opposition. So Democrats are appalled by what he is doing to immigrants, and therefore may go beyond calling for the legalization of people who have been here a long time and move all the way to decriminalizing border crossings, because they see people in cages.” The party’s leftward drift, Rhodes said, “is both an emotional and intellectual response to Trump.”
That phenomenon was on full display during the first two debates, in which the most liberal candidates—such as Cory Booker, Bill de Blasio, Bernie Sanders, and to a lesser degree, Kamala Harris—portrayed both Clinton and Obama policies in a shockingly negative light.