This has to be a major factor. Conservative media has focused heavily on campus protests, free-speech clashes, and debates over (for example) whether offering ethnic food in dining halls constitutes cultural appropriation. Multiple states have introduced legislation designed to protect unpopular speakers, taking up model legislation circulated by a think tank.

Still, I’m skeptical that this explains all of the change. After all, to mix a metaphor, conservative leaders have used the Ivory Tower as a punching bag for decades, at least since William F. Buckley began using his famous quip about preferring government by the first 2,000 names in the Boston phonebook to a regime of Harvard professors, a quip that dates itself by invoking phonebooks (but appears to date to the early 1960s). Campuses have also been battlegrounds for culture wars since then, and no acrimony today can match the battles at Berkeley or Kent State in the 1960s and 1970s, though it’s true that conservative media is also far stronger now. Unfortunately, there’s not a great deal of corroborating evidence to draw on, either. While some polls—including Pew—have measured support for hate-speech codes among Millennials, that doesn’t tell us anything concrete about the backlash. A steep drop in enrollment at the University of Missouri reached the headlines recently, a ripple effect of huge protests there, but there isn’t a corresponding drop in attendance around the country.

So if “safe spaces” account for only some of the shift, what else might be at work? One theory that seems to make a lot of sense is that the composition of the Republican/Republican-leaning demographic has shifted. (For simplicity, let’s just call them the Republicans from here on out. Pollsters and political scientists have long ago shown that while a growing number of Americans identify as independents, most of them vote pretty consistently for one party or the other.)

This is alluring because it fits with the fact that, as Nate Silver has written, “it appears as though educational levels are the critical factor in predicting shifts in the vote between 2012 and 2016.” If the voters who Trump picked up over Mitt Romney are more likely not to have a college education, it isn’t surprising that they would have less attachment to the role of colleges and universities. However, as Pew’s Jocelyn Kiley pointed out to me, Pew hasn’t found a huge shift in partisan identification to match the change. Besides, positive feeling about colleges and universities has slid among all Republican demographics.

Trump might bear closer examination as a driver, though, even if it doesn’t come through in changing party composition. Over the period in which Pew measured the enormous switch, the president has been by far the most potent force in Republican politics, showing that he could overcome the party establishment and much of the conservative media. That allowed him to reverse long-held GOP stands on certain issues—not just in the platform, but in the minds of Republican voters, too. Not long ago, free trade was a bedrock belief of the GOP. Yet consider this Pew result from last August: