Many faculty leaders have worried that this week's hearings by a Pennsylvania legislative committee would turn into just the kind of professorial inquisition that they have feared the "Academic Bill of Rights" might set off.
But as hearings ended in Philadelphia Tuesday, critics of the Academic Bill of Rights were saying that they had scored key points. David Horowitz, the conservative activist who has led the push for the hearings in Pennsylvania and elsewhere, admitted that he had no evidence to back up two of the stories he has told multiple times to back up his charges that political bias is rampant in higher education.
In an interview after the hearing, Horowitz said that his acknowledgements were inconsequential, and he complained about "nit picking" by his critics. But while Horowitz was declaring the hearings "a great victory" for his cause, he lost some powerful stories. For example, Horowitz has said several times that a biology professor at Pennsylvania State University used a class session just before the 2004 election to show the Michael Moore documentary Fahrenheit 9/11, but he acknowledged Tuesday that he didn't have any proof that this took place.
In a phone interview, Horowitz said that he had heard about the alleged incident from a legislative staffer and that there was no evidence to back up the claim. He added, however, that "everybody who is familiar with universities knows that there is a widespread practice of professors venting about foreign policy even when their classes aren't about foreign policy" and that the lack of evidence on Penn State doesn't mean there isn't a problem.
"These are nit picking, irrelevant attacks," he said.
Others think that it's quite relevant that Horowitz couldn't back up the example, especially since there have been previous incidents in which his claims about professors have been debunked. 
"So much of what he has said previously has been exposed to be lies or distortions that it makes any of his examples questionable," said Jamie Horwitz, a spokesman for the American Federation of Teachers. The lack of evidence about the Penn State and other examples "should give this committee and any committee anywhere in the country pause about considering an Academic Bill of Rights," he added. "The bottom line is that there's not a lot of there there."
The Academic Bill of Rights  is a short statement that calls for colleges to respect the rights of students and professors to have a variety of political views and not to have their academic work judged on the basis of those views. While few professors object to such a statement, other parts of the Academic Bill of Rights, which call on faculty members to share a range of views with students, have been much more controversial. Many professors believe that this language could lead to lawsuits, legislative oversight and pressure to teach viewpoints like creationism or Holocaust denial that they believe have no place in a classroom.
The stories like the one about the Penn State professor who allegedly made his class watch Fahrenheit 9/11 have been an important part of the debate over the Academic Bill of Rights. Horowitz and many other conservative critics of higher education point to numerous studies  that show that college professors are, on average, more liberal than the general public and that conservative academics are a minority group at most colleges.
While many faculty groups have criticized these studies, they generally haven't disputed the idea that academics lean to the left. What they have disputed is that these leanings result in ideological discrimination against students or professors who think differently. As a result, an example that would suggest bias -- like, say, a professor screening an anti-Bush film in a biology class -- have considerable political currency.
The other example Horowitz was forced to back down on Tuesday is from the opposite end of the political spectrum. He has several times cited the example of a student in California who supports abortion rights and who said that he was punished with a low grade by a professor who opposed abortion. Asked about this example, Horowitz said that he had no evidence to back up the student's claim.
In the interview, he said that he didn't have the resources to look into all the complaints that he publicizes. "I can't investigate every story," he said.
Horowitz noted that when he publicizes such stories, he does not print the names of the professors involved, and that he has stated many times that a professor involved in such an incident would be welcome to write a rebuttal that he would post on his Web site. "I have protected professors. I have not posted their names and pilloried them. My Web site is open to them," he said.
Even if these examples aren't correct, he said, they represent the reality of academic life. "Is there anybody out there who will say that professors don't attack Bush in biology classrooms?" he said. Horowitz characterized the debate over his retractions as a diversionary tactic by his critics. "First they say that there is no problem [with political bias]. Then they say I'm a McCarthyite. Then they say I'm spreading false rumors. Everyone who is in public life and makes commentaries makes mistakes."