A new executive order from the White House will aim to make federal research funding for colleges and universities contingent on their support for “free speech,” President Trump said Saturday.

The announcement, during Trump’s address to the Conservative Political Action Conference, appeared to target complaints by some university critics that institutions of higher education stifle right-wing viewpoints.

“If they want our dollars, and we give it to them by the billions, they’ve got to allow people like Hayden and many great young people, and old people, to speak,” Trump said, bringing onstage a young conservative, Hayden Williams, who was physically attacked last month while tabling for a conservative organization at the University of California at Berkeley.

The executive order, Trump said, would “require colleges to support free speech if they want federal research” money. The White House did not immediately respond to a request for comment.

Trump told the CPAC crowd, meeting at National Harbor, Md., that he planned to sign the order “very soon” but did not provide specifics or say whether a draft has already been prepared.

The federal government distributes more than $26 billion a year to colleges and universities for research purposes, according to the National Science Foundation. The vast majority of that money is assigned to projects for the Pentagon, NASA, and the departments of Agriculture, Energy, and Health and Human Services.

Trump is likely on strong footing with the proposed executive order, said Cynthia Miller-Idriss, a professor of education at American University.

“There’s a history of the federal government requiring universities to do certain kinds of things in order to receive federal research funding,” she said. For example, she said, the U.S. government imposes ethical guidelines on studies involving human subjects.

But the order could disproportionately affect private colleges and universities over public ones, Miller-Idriss added, because those institutions have historically enjoyed greater leeway to determine who may speak on campus.

“If I had to wager a guess at this point,” she said, “I would say probably [the order] would be asking for private universities to follow the same kinds of things state universities have had to do, which is basically to say that if you rent space publicly, for example, you can’t control who rents that space.”

Other experts said Trump’s proposal raised serious First Amendment concerns.

“Somebody would have to decide which universities were not supporting free speech on campus,” said Catherine Ross, a professor in constitutional law at George Washington University. “Some group of Washington civil servants — or maybe even worse, political appointees — would be looking at charges of speech discrimination at various colleges and universities, and labeling them as either acceptable in terms of free speech or not acceptable. And that … is a government interference in speech.”

What’s more, she added, Trump’s policy could inadvertently disqualify many religious academic institutions from receiving federal research funding, to the extent that their religious beliefs prohibit certain views or speakers on campus.

Higher education groups swiftly pushed back against Trump’s proposed order.

“This is a solution in search of a problem that will create its own problems,” said Terry W. Hartle, senior vice president for the American Council on Education, which represents college and university presidents. “Free speech is a core value for research universities because it’s tied up with academic freedom. Controversies do arise, but they tend to be relatively infrequent.”

Standing onstage together, Trump praised Williams and urged him to sue the University of California at Berkeley over the incident. A university spokeswoman didn’t immediately respond to a request for comment.

Nick Anderson contributed to this report.