Four national groups representing college educators and trustees said Thursday they would fight a growing push in state legislatures to allow people to carry concealed guns on campuses.

The groups also called for the repeal of measures in several states that already allow for so-called campus carry, arguing that academic institutions should remain "as safe and weapon-free as possible for students, faculty, staff, parents and community members."

"Colleges and universities closely control firearms and prohibit concealed guns on their campuses because they regard the presence of weapons as incompatible with their educational missions," said the statement, signed by the American Association of University Professors, the American Federation of Teachers, the Association of American Colleges and Universities and the Association of Governing Boards of Universities and Colleges.

The groups said students and professors wouldn't be comfortable discussing controversial subjects if they thought there might be a gun in the room. "College campuses are marketplaces of ideas, and a rigorous academic exchange of ideas may be chilled by the presence of weapons," they said.

Supporters such as the National Rifle Association argue that lawful gun owners should be allowed to carry on campuses for self-protection. They argue that having more law-abiding citizens with guns could potentially deter mass shootings or allow bystanders to intervene to limit the deadly consequences.

The statement from the four groups comes amid intensifying debate over how to prevent gun violence on campuses, following last month's shooting at Umpqua Community College in Oregon. Lawmakers in Florida are considering plans to allow concealed permit owners to bring their guns onto campus, and several other states are expected to consider similar legislation next year.

Texas recently became the eighth state to allow the carrying of concealed weapons on campuses, according to the National Conference of State Legislatures. The change goes into effect next year, and colleges are considering how to implement it. The law contains a key concession for opponents, giving administrators the ability to mark off certain areas as gun-free.

Seven other states — Colorado, Idaho, Kansas, Mississippi, Oregon, Utah and Wisconsin — now have laws or court rulings allowing the carrying of concealed weapons on some campuses, according to the NCSL.

The higher education groups rejected the argument that more guns could deter mass shootings. They called on colleges and universities to plan for critical incidents, and "rely on trained and equipped professional law-enforcement personnel to respond to emergency incidents."

Students for Concealed Carry, a group that is pushing for campus carry laws in several states, said the laws don't have as much of an impact as critics claim. Few students can qualify to carry weapons because they aren't 21, and those who do have obtained licenses and undergone background checks, spokesman Zachary Zalneraitis said.

"The people in charge, the administrators and professors, are always resistant to it," he said. "But after it gets passed, it just becomes a non-issue."