The University of Missouri won't fire an assistant professor of communications, school officials say, even though the professor, Melissa Click, has been charged with assault for blocking a student reporter who was trying to take video of protests on campus.

That's a reasonable policy decision because everyone's entitled to the presumption of innocence. At the same time, the university's acting chancellor, Henry Foley, said something calculated to strike fear in the hearts of untenured professors everywhere: He indicated that the university would take account of her actions when she's being considered for tenure.

Is that legal? Assuming it is, does considering Click's behavior in the tenure decision respect her academic freedom? The answers to these questions aren't simple.

The bottom line is that a public university may not consider a candidate's political opinions in deciding on tenure. And no university, even a private one, should do so.

Behavior and judgment, on the other hand, are legitimate subjects for consideration. Click's tenure may therefore be in doubt independent of her academic work.

Start with the law. The University of Missouri is a state-run entity bound by the First Amendment. In fact, its public status is part of what made Click's behavior substantively wrong in the first place. The protest that the student reporter, Mark Schierbecker, was trying to cover took place on a patch of grass within the university's campus. Schierbecker was therefore correct when he told Click that he was on public property.

At a private university, the situation might well have been different. Freedom of the press wouldn't necessarily apply; it would have been up to the university to decide whether reporters could cover the events and whether they could be there at all. As a university employee, a professor could in theory have been empowered to enforce the university's policy, whatever it may have been.

The University of Missouri, however, couldn't do that. Click could conceivably have been charged with the civil rights violation of trying to suppress Schierbecker's free speech. Indeed, that charge seems closest to capturing what was wrong with her actions: She was trying to suppress the First Amendment freedom of the press. A civil suit against the university by the reporter wouldn't be out of the question if Click's actions were understood to have been taken under color of law.

But Click hasn't been charged by federal authorities with a civil rights violation. She's been charged by the state prosecutor with misdemeanor criminal assault. It's hard to know whether she will be found guilty. In the video, it seems she touches Schierbecker's camera or arm in trying to make him put it away. Then she calls out to other protesters for "some muscle" to get rid of him. This might be enough for third-degree misdemeanor criminal assault under the law, which makes it a crime to attempt to cause physical injury to another person or to intentionally engage in "physical contact with another person knowing the other person will regard the contact as offensive or provocative."

Regardless of whether Click is convicted, what aspects of the episode can be considered by the university at tenure time? To be clear, the university can't punish Click for supporting the protesters, which is a political viewpoint protected by the First Amendment.

A professor's free-speech rights in tenure review are tricky. In general, when the government makes decisions based on the content of speech, it's held to the high standard of "strict scrutiny." The state must show that it has a compelling interest and that its actions are narrowly tailored to achieve that interest.

But that standard can't be the right one for academic tenure decisions. All tenure review involves assessing the content of the candidate's speech. If it's high-quality enough to match the institution's standards, and there's enough of it, the professor should get tenure. If the content is academically weak and below standards, not to mention if the quantity is insufficient, tenure denial is appropriate. The university can't make these academic judgments without considering content.

Nevertheless, even under a lower standard of scrutiny, a public university can't discriminate against certain political viewpoints. It would be unconstitutional for the public university to deny tenure to someone whose work is of high quality and quantity because of the political stance adopted by the scholar.

A private university could legally discriminate based on political viewpoint. But doing so would violate the cardinal principle of academic freedom. Academic freedom isn't the right to get tenure no matter what you've said. Low-quality work isn't protected. Yet academic freedom means, at a minimum, that a tenure decision won't depend on the politics of the candidate's work.

The university may, however, consider Click's actions in the framework of her judgment. It may consider a criminal conviction or even just a charge of assault against a student. The challenge will be to separate this legitimate assessment from an opinion of her politics. And if she's shown evidence of better judgment in other contexts, it should be treated as a counterweight.

In practice, though, Click now has reason to be worried. Being an untenured professor is a vulnerable position. Advocates of academic freedom and free speech should be vigilant to make sure she's treated fairly. But Click's moment of disrespect for free speech may turn out to have been costly to her own interests.

Noah Feldman is a Bloomberg View columnist.