U.S. Attorney General Jeff Sessions delivered a powerful message last week in support of free speech on college campuses, warning that the American university is being transformed into an “echo chamber of political correctness and homogeneous thought.” He also promised that the Justice Department would support students who have gone to court to challenge restrictions on their speech.

There was a lot of truth in the attorney general’s indictment, delivered Tuesday in a speech at the Georgetown University Law Center. We too have expressed concerns that controversial speakers might be silenced because universities fear violent protests, effectively granting protesters a “heckler’s veto.” We too have criticized college administrations that have confined students expressing their opinions and passing out literature to tiny “free speech zones.”

But while we find much to admire in the attorney general’s message, he is a flawed messenger. We worry that Sessions’ embrace of free speech on campus — and his plan to deploy the Justice Department in vindicating it — might be designed to protect only conservative speech or to score political points with those on the right.

In extolling the importance of free speech on campus, Sessions was careful to stress that the Justice Department under his leadership would “enforce federal law, defend free speech and protect students’ free expression from whatever end of the political spectrum it may come.” But most prominent targets of campus protests and blockades — and worse — have been conservative figures.

That imbalance is not Sessions’ fault. It’s a reflection of the fact that, at least at highly competitive universities, the prevailing point of view is liberal and dissenting views are often conservative.

But if Sessions’ free-speech campaign is to be credible, it mustn’t be applied in an ideological or politically motivated manner. It’s especially important that the Justice Department be absolutely evenhanded in filing “statements of interest” siding with students who have challenged policies at universities that restrict freedom of speech.