Why should we continue to help fund schools that don’t allow a free exchange of ideas?

During a recent speech to the Conservative Political Action Conference, President Trump floated the idea of an executive order withholding federal research dollars from schools that don’t protect speech and free inquiry. Conservatives rightly cheered, but there’s more to be done to preserve and advance right-of-center views on the quad.

Left-wing academe and its media cheerleaders, of course, don’t even acknowledge there’s a problem. A piece in the Washington Post following Trump’s speech was headlined: “Questions abound after Trump threatens to strip funding from colleges that don’t support free speech.”

The article quoted many people ostensibly supportive of free speech who were nevertheless concerned about Trump’s plan.

They don’t get it.

Jonathan Friedman, campus free-speech project director for PEN America, was quoted as saying that “colleges are not the enemy of free speech that this administration has sometimes made them out to be.”

But they are exactly that. Colleges are educating a generation of young adults who can’t hear ­opposing viewpoints. That this is dangerous to freedom of speech should be obvious.

Sigal Ben-Porath, a professor of education, political science and philosophy at the University of Pennsylvania, was also quoted in the Washington Post’s report, warning that Trump’s proposal is “thought-police territory.”

Ben-Porath has written a book ­titled “Free Speech on Campus,” yet she treats efforts to protect viewpoint diversity on campus as somehow straight out of a dystopian future. Ben-Porath has previously referred to “the focus on free speech as a wedge issue” and ­argued that free speech on campus is not under attack.

Again, this is plainly untrue — as any conservative or libertarian speaker who has ever been invited to speak on a university campus knows. Nowadays, it’s rare when such invitations aren’t met with calls for censorship, physical ­intimidation and violence and eventual dis-invitations.

Civility is hard to come by when no outside viewpoints are ­allowed, and the best-endowed universities could even withstand it if Trump made good on his threat. That’s why other initiatives are needed.

A relatively new group, Heterodox Academy, was formed by “more than 2,500 professors, ­administrators and graduate students” to promote viewpoint ­diversity on campuses, because that’s no longer something people expect from institutions of higher learning. These aren’t necessarily conservatives — just scholars and thinkers whose ideas for whatever reason run afoul of the latest ­intersectionality doctrines.

That such a group is so needed in colleges today, and that their goal seems like such a steep climb, is the crux of the problem. The ideological uniformity they’re fighting is exactly what leads to a shutdown of speech. When no one has a differing opinion, it’s easy to see disagreement as some sort of attack.

The argument for allowing speech has progressed far beyond wanting civility. Debate would be great, but at the moment conservatives on campus would probably settle for simply being allowed to speak at all.

Last week, a blogger named Michael Strickland was invited to speak on campus by the College Republicans at Portland State University. A protester with a bell ­impeded him from doing so and proudly proclaimed that he had shut down the event. Journalist Andy Ngo filmed the exchange.

Campus police were on hand during Strickland’s talk, but the ­officers didn’t get involved.

If a college can’t prevent a bell-ringing dingbat from stopping a speech, what’s the point of that school at all?

And why do we continue to pay them for their uselessness? This is exactly the kind of incident that should get a college stripped of its federal funding.

The schools that stand by while speech gets shut down on their campuses — or, worse, engage in direct censorship — shouldn’t ­receive our tax dollars to help them do that.

Conservatives are in a precarious enough position in higher education, and as they beat back indoctrination by their professors, and violence and extreme marginalization against their viewpoints, they shouldn’t also have to pay for the privilege.

A free exchange of ideas should be the goal, and here’s hoping groups like Heterodox Academy can achieve it. But meanwhile, colleges at a minimum should be forced to protect the freedom of people to simply speak.