Ward Churchill, who was interrupted several times by thunderous applause, went ahead with the speech after the University of Colorado backed off an attempt to cancel the address, citing security reasons. Churchill had filed a lawsuit against the cancellation.
Churchill's comments, which appeared in an essay he wrote soon after the Sept. 11, 2001, terror attacks, prompted a firestorm of criticism when they became widely known last month, prompting him to resign as chairman of Colorado University's ethnic studies department.
Gov. Bill Owens has called for Churchill to be fired, and the university's Board of Regents is investigating whether the tenured professor can be removed — though he has vowed to go to court if it tries to do so.
"I don't answer to Bill Owens. I do not answer to the Board of Regents in the way they think I do. The regents should do their job and let me do mine," Churchill told the audience Tuesday night. "I'm not backing up an inch. I owe no one an apology."
In the essay, Churchill wrote that some of the workers in the World Trade Center were the equivalent of "little Eichmanns," a reference to Adolf Eichmann, who ensured the smooth running of the Nazi system. Churchill also spoke of the "gallant sacrifices" of the "combat teams" that struck America.
Churchill told The Associated Press before the speech that he mourns for everyone killed on Sept. 11 and conceded that he could have explained himself better.
He said he was referring to "technocrats" who participate in what he calls repressive American policies around the world and — like Eichmann — supported an immoral system.
Eichmann "did not necessarily agree with the goals of the Nazis with regard to the Jews, but he performed his functions brilliantly," Churchill said. "This is Eichmann: He's integral. The Holocaust could not have happened without him."
He pointed to U.N. trade sanctions on Iraq during the Saddam Hussein regime, which have been blamed for the deaths of 500,000 children. "If someone were to ask me, 'Do you feel sorrow for the victims of 9-11,' of course I do," he said. "Let's begin with the children. Yes, they were innocent. And I mourn them. But they were not more innocent than those half-million Iraqi children."
During his 35-minute speech, Churchill said the essay was not referring to children, firefighters, janitors or people passing by the World Trade Center who were killed during the attacks.
Churchill's essay and a follow-up book attracted little attention until he was invited to speak last month at Hamilton College in New York state, which later canceled his talk out of security concerns after a professor at the college found the essay and pointed it out to the school newspaper.
University of Colorado officials cited those same concerns but backed off after Churchill filed a lawsuit earlier Tuesday. About two dozen police officers were scattered inside and around the ballroom where the speech was given.
KCNC-TV Reporter Rick Salinger tells CBS News' Early Show scuffles broke out last week when supporters of Churchill were not allowed to speak at a university board of regents meeting.
Scholars worry the backlash will leave other professors fearful of challenging conventional opinion.
"We recognize that academic freedom comes with limits, but we also know that any interference with academic freedom without strong cause sends a very chilling message to the entire academic community," said Barbara Bintliff, chairwoman of the Boulder Faculty Assembly.
David Horowitz, a champion of conservative causes who has long accused American universities of overstocking their faculties with leftists, said firing Churchill would violate his constitutional free speech rights and set a bad precedent.
He called instead for an inquiry into the university's hiring and promotion procedures "to see how Ward Churchill could get to the pinnacle of the faculty, to be the chair of an entire department."
"This isn't like a guy who was suddenly exposed," Horowitz said. "This is a guy who's been out in the open for 30 years and was promoted."