NEW YORK (AP) – Conservative author David Horowitz spoke at Columbia University amid tightened security Friday – the latest in a string of political lightning rods to appear at the Ivy League school.

Horowitz appeared at the school as part of the so-called Islamo-Fascism Awareness Week on college campuses, intended to foster awareness of terrorism. But some Muslims say the week’s activities are fostering racism instead.

Horowitz, a self-described former Marxist, said the week was an effort to distinguish “moderate Muslims” from “Islamo-Fascists.”

“This is nothing that could remotely be interpreted as an attack on Muslims. It’s a defense of moderate Muslims,” he told a peaceful lecture-hall audience of about 100 students and visitors.

The California-based activist, known for his ads in campus newspapers opposing slavery reparations, was invited to Columbia by the College Republicans, who on Friday kept track of each person entering Lerner Hall – against a list of names submitted in advance. The audience included people who disagreed with Horowitz’s positions.

Last month, Iranian President Mahmoud Ahmadinejad caused an uproar when he was invited to speak at Columbia. He faced tough questioning and the university’s president introduced him by saying Ahmadinejad exhibited “all the signs of a petty and cruel dictator.”

And last year, the College Republicans invited the founder of the California-based Minutemen Project, Jim Gilchrist. He was forced off the stage by protesting students. Gilchrist was invited back earlier this year, but the speech was canceled under pressure from student activists.

Horowitz, author of “Indoctrination U: The Left’s War Against Academic Freedom,” and other books, gave an hour-long speech where he outlined his views on the role of Muslim fundamentalists through history, emphasizing the current danger of a group of people he said are “out to kill Americans.”

He said discussion of this subject has been “banished” from classrooms at Columbia, his alma mater. The school hires mostly “progressive” professors, he said, while failing to employ teachers who might offer students “diverse” ideas.

“The professor has an obligation to provide students with texts that provide diverse points of view,” he said.

By contrast, when he was a Columbia student “50 years ago,” Horowitz said, “I wrote Marxist papers for professors who were undoubtedly anti-communist.”

Columbia officials declined to comment on Horowitz’s statements.

The event drew a small group of protesters and activists. One protester, a senior majoring in religious studies, called Horowitz “a demagogue opposed to reasonable discourse.”

Joshua Schwartz, 21, said his view of Islamic fundamentalists as dangerous “comes from an old tradition of associating Islam with barbarism and violence.”

Sunsara Taylor, who joined the protest but is not a student, went one step further. Horowitz, she said, is “on a witch hunt to purge academia of professors who don’t agree with him.”

The controversy at the school hasn’t been limited to speakers. Earlier this month, a noose was strung on the door of a black professor’s office. No arrest has been made in the case.

AP-ES-10-26-07 1953EDT