The list of things President Trump has threatened to defund includes sanctuary cities, Planned Parenthood, NASA climate research and, now, the University of California at Berkeley.

Before heading to the National Prayer Breakfast on Thursday, Trump floated the idea of stripping federal funding from Berkeley, where a protest against a scheduled appearance by Breitbart writer Milo Yiannopoulos the previous night led to violence and vandalism. The university canceled Yiannopoulos's speaking engagement before it began, citing safety concerns.

Perhaps the president had started his morning by tuning in to Fox News. Shortly before Trump sent his tweet, commentator Todd Starnes had said that “President Trump should immediately issue an executive order blocking Berkeley students from receiving any federal funding. Same goes for any other public university that wants to silence conservative voices. Free speech for all or no federal money, not a single taxpayer penny, period.”

As The Fix's Aaron Blake has noted, Trump has a habit of tweeting policy proposals soon after he sees them on TV.

For perspective, $417.3 million of Berkeley's $1.79 billion in operating revenue, 23 percent, came from federal grants and contracts during the 2015 fiscal year, the most recent year for which there is an annual report on the university's website. So, we're talking about a big chunk of the budget here.

One-third of Berkeley undergrads receive federal Pell grants. That's more than 9,000 students. Campus police estimated the protesters numbered about 1,500, including non-students and the vast majority of demonstrators who did not smash windows or start a fire.

“I do not believe our students were involved in the vandalism and the violent behavior that occurred,” the university's police chief, Margo Bennet, told reporters. “This was a group of agitators who were masked up, throwing rocks, commercial-grade fireworks and Molotov cocktails at officers. Those were not our students. That's not our students' behavior.”

It is, of course, virtually impossible for Bennet to know for sure whether these “agitators,” many of whom wore masks, were students or not. Only one person was arrested.

What is clear, however, is that cutting off Berkeley's federal funding would penalize thousands of innocent students.

Moreover, Trump cast Wednesday's ugly episode as evidence that “Berkeley does not allow free speech” when it is exactly the opposite. That the university agreed to host Yiannopoulos in the first place is a sign of its commitment to free speech, which the school reiterated in a statement condemning “the violence and unlawful behavior that was on display.”

While Mr. Yiannopoulos's views, tactics and rhetoric are profoundly contrary to our own, we are bound by the Constitution, the law, our values, and the campus's Principles of Community to enable free expression across the full spectrum of opinion and perspective.

Berkeley surely knew that what happened Wednesday night was a possibility. Yiannopoulos is a frequent speaker on college campuses, and protests follow him everywhere. Just a couple of weeks ago, the University of California at Davis called off an appearance by Yiannopoulos because a protest created a dangerous environment.

Despite the threat of damage to its campus, Berkeley kept Yiannopoulos on the docket, beefed up security, and only pulled the plug when the atmosphere became unsafe.

So, while the thought of defunding Berkeley might thrill Trump's supporters, it would make no sense to actually do it.