The Supreme Court is turning back a challenge from conservative college students who say their freedom of speech is violated by a university program for reporting allegations of bias.

The U.S. Supreme Court on Monday declined to hear a case on college programs which a conservative group claimed chills free speech and pushes students to be fearful to express an unpopular or controversial viewpoint.

Justice Clarence Thomas on Monday called for the Supreme Court to review bias response teams on college campuses out of concern they stifle free speech rights.

The Supreme Court on Monday declined to hear a challenge to Indiana University’s use of a “bias response team,” prompting a dissent from Justice Clarence Thomas, who argued the case was an important opportunity to resolve a split among federal courts over whether such programs infringe on student free speech rights.