By now, it’s clear that the 2015-era decline was not a blip, and it was likely some combination of the above that took Republicans from being collectively pro-college to anti-college over the course of the 2010s. It’s not obvious what precisely changed—especially to cause that mid-decade drop-off—but some experts who follow the politics of college see in this shift the culmination of conservatives’ decades-long work to undermine the status of higher education.

Amy Binder, a sociologist at UC San Diego and a co-author of Becoming Right: How Campuses Shape Young Conservatives, cites the “wide availability of critiques of higher ed” as a potential cause of this shift. Here, she was thinking of the ideas emanating from conservative student-focused organizations such as Turning Point USA and Young America’s Foundation, academic internet sensations such as Jordan Peterson and Christina Hoff Sommers, and Fox News; all tend to promote the notion that campuses are inhospitable for conservatives.

Their narrative isn’t new—though it might be newly widespread. “What was it about 2015 that really started turning the tide?,” Binder says. “I just can’t pinpoint exactly what it is. Outside organizations’ attacks on higher education vastly predate these new trends in how the public perceives higher education.”

Binder thinks colleges might be a compelling political target to Republicans because conservatives are so rarely in control of them. “The academy is one area of American life that conservatives have most definitely not captured,” she told me.

The critiques also capitalize on the skepticism Americans have long held toward book-learning. “Americans may love on some level the notion of having some of the greatest universities in the world, but basically we like practical things, as opposed to the life of the mind, which is seen as slightly European, elitist, [and] not quite connected to the larger culture,” says William Reese, a professor of educational-policy studies and history at the University of Wisconsin–Madison.

The experts I talked with pointed to recurring examples of anti-college rhetoric from the ’50s to the pre-Trump 2010s—it has regularly (and unsurprisingly) flared up over the years. (Pew’s data only goes back to 2010, so it’s hard to compare the views of today’s public with those of past Americas.)

This is the historical undercurrent that today’s messaging carries forward. Jonathan Zimmerman, a professor at the University of Pennsylvania’s Graduate School of Education, says of Fox News’s coverage, “Every story about [a] university is essentially the same: Somebody on the left did or said a censorious thing that in some way victimizes a conservative.” Given how prominently universities feature in conservative media as examples of what’s wrong with America, Zimmerman says, he’s surprised that there aren’t even fewer Republicans who hold colleges in high regard.