Fill one of these out, carry a gun on a college campus.

Monday, Texas public universities ushered in the first day of a new reality. Anyone on campus licensed to carry a handgun is now legally allowed to do so on portions of state owned, four-year college campuses, thanks to a bill passed during the 2015 legislative session.

On Tuesday, Texas Attorney General Ken Paxton took his best shot at the last-ditch lawsuit filed by three University of Texas professors to keep guns out of their classrooms.

The professors — Jennifer Lynn Glass, Lisa Moore and Mia Carter — say that allowing guns on campus stifles their ability to teach controversial subjects in their classrooms and denies them the equal protection they are guaranteed by the 14th Amendment.

Paxton calls the professors’ first amendment claims “independently fatal.” “To be sure, Plaintiffs have First Amendment rights as to their academic research, their out-of-class public statements, and a plethora of other forms of expression,” Paxton writes in his response to their lawsuit. “But this case is not about any of that. Plaintiffs have alleged a violation of their right to academic freedom, with a focus on their classroom curriculum and instruction. On those matters, Plaintiffs do not have an individual First Amendment right to academic freedom — their institution, the University of Texas, does.”

UCLA Law Professor and constitutional expert Eugene Volokh told the Observer in July that the lawsuit was unlikely to stand up for a different reason; because it isn’t explicitly targeted at limiting speech.

“I’m skeptical about the plaintiffs’ claims that concealed carry by lawful license holders will materially chill people’s freedom of discussion,” he said. “I don’t think it does in public places, and I don’t think it will in universities. But in any event that hypothetical risk isn’t enough to invalidate Texas’s decision about gun rights.”

UT’s new policy allows professors to ban guns from their personal offices, but requires that firearms be allowed in classrooms and most campus buildings. Guns are not, however, being allowed in dorms. Nor are they allowed in the UT clock tower, where Charles Whitman murdered 14 people with a rifle. The first day of campus carry, August 1, 2016, is 50 years to the day of that infamous mass shooting.