David Horowitz is getting backing from his usual critics after Saint Louis University sought to change or block (depending on who you are talking to) a planned lecture he was scheduled to give next week on the campus.

The event -- "An Evening with David Horowitz: Islamo-Fascism Awareness and Civil Rights" -- was organized by the College Republications and Young America's Foundation, which say they were banned from hosting Horowitz. The university denies that it banned Horowitz, but acknowledges that it told the students that they should modify the event.

"University officials expressed concern that the program in its current form could be viewed as attacking another faith and seeking to cause derision on campus," said a university statement. "Believing that this was not their intent, University officials offered the students several suggestions to modify their program in a way that could achieve their aims while remaining true to the university's Catholic, Jesuit mission and values. Among the suggestions was that the students engage scholars with expertise on historical and theological aspects of Islam to help prepare their program."

The university says that it cannot be said to have banned the talk because it was still in discussions with student groups about the issue when they decided not to continue the negotiations.

Horowitz's talks about Islam and what he calls "Islamo-Fascism" have been controversial, with many saying that he distorts history in a way that denigrates all Muslims. But he is also a popular speaker with conservative groups, who regularly bring him to campuses to speak. On some campuses, his appearances prompt protests, but at other campuses he ends up largely speaking to those who agree with him.

Cary Nelson, national president of the American Association of University Professors, issued a statement on the association's Web site, denouncing the university in harsh terms.

"Now that Saint Louis University has cancelled a scheduled October speech by conservative activist David Horowitz, it joins the small group of campuses that are universities in name only," Nelson wrote.

"The free exchange of ideas is not just a comforting offshoot of higher education; it defines the fundamental nature of the enterprise. As the AAUP has long asserted, all recognized campus groups have the right to invite any speakers they wish. The College Republicans exercised that right. There should not have been a mechanism in place for the administration to review the offer to Horowitz and withdraw it. The administration’s claim to support academic freedom has been hollowed out by the practical and symbolic effects of this one public act," said Nelson. "A campus that enforces ideological conformity supports indoctrination, not education."

Nelson and Horowitz have long criticized one another's views of higher education. Likewise, another Horowitz critic -- John K. Wilson -- criticized Saint Louis University on his blog, College Freedom. Wilson quoted from exchanges between the student organizers and Horowitz, which suggest that the university's decision was based on opposition to Horowitz's views.

"If the administration at SLU disagrees with Horowitz (and I hope they do), then they are free to express their opposition," he wrote. "They are free to attend Horowitz's lecture and criticize him. They are free to boycott Horowitz's lecture and denounce him. They are free to invite a speaker every day of the week to come to campus and refute what Horowitz says (I'll volunteer to be first in line). But they are not free, in any university worthy of the name, to suppress a speaker because he is offensive and wrong."

Horowitz said via e-mail that university officials had suggested that he calls as Muslims fascists, which Horowitz said was a "gross and demonstrable lie." He called the university's action "raw censorship" but said he was "pleased to see the AAUP defending me, as they should."