Where is the line? What can conservatives say about homosexuality that won’t be considered bigotry? The case of Professor John McAdams has lit up the conservative intellectual world with its implications for the eroding respectability of conservative opposition to gay rights and the utterly transformed intellectual environment on US college campuses.

Let’s start with a few caveats. First, full disclosure: I taught one semester at Marquette University, Professor McAdams’s school. I also taught for several years down the street at Marquette High School, which is no longer directly connected to the university. I feel an abiding love for both institutions. More important, I am unapologetically biased in this case. I believe it is legitimate and important to regulate speech in public (and some private) forums, including college classrooms. Hard as it is to hear, some ideas do not deserve to be granted equal status with others. Ideas that dehumanize classes of people are not just as good as other ideas. For instance, if a student in a seminar wants to insist that no white people can possibly understand US history because they are by definition part of an exploitative class, such talk should be ruled out of bounds. It would tend to exclude an entire class of people simply because of their cultural identity. Similarly, if a student wanted to rule that homosexuals were incapable of being moral in their relationships, or that women cannot understand certain concepts, or that non-citizens have no right to be heard in political discussions, such talk should be out of bounds.

Of course, many conservative intellectuals share that basic framework, but they disagree bitterly that traditionalist notions about homosexuality constitute that same sort of exclusionary mentality. In other words, many conservative thinkers agree that public speech shouldn’t be racist or chauvinist, but they disagree that conservative ideas about homosexuality fall into that same category.

The steamroller drive of homosexual rights in recent months and years has put some traditionalist conservatives on edge. A few recent cases have raised hackles among many conservative thinkers. At Mozilla and Gordon College, to cite just two examples, conservative intellectuals attracted instant and furious retribution for statements that have been perceived as anti-gay. In each case, ideas that would have been unremarkable just a few years ago are now taken as beyond the pale of respectable public speech.

In the case of Professor McAdams, college politics and bureaucracy have added new wrinkles into the question of acceptable conservative opinion about homosexuality. In brief, McAdams has been suspended with pay and asked to stay away from campus. Why? He blogged about the statements of a teaching assistant. That TA had told a student that opposition to homosexual marriage would not be considered in a class on ethics. The student complained to Professor McAdams, and McAdams outed the TA on his blog.

As McAdams noted, his support for the student prompted furious condemnation by “leftist academics,” who “demanded our head on a pike.” A group of prominent faculty at Marquette published an open letter on the issue. McAdams’s actions, they write, constituted “harassment and intimidation” of the TA. Other members of the Marquette community, they write, altered their behavior to avoid similar attacks from McAdams.

In the end, McAdams has been suspended with pay. The Fox-News commentariat has had its chance to recoil in horror at the anti-conservative “inquisition.”

There is, of course, more at stake here than intellectual positions about homosexuality and gay rights. We also must consider faculty politics and the unfortunate ways academics learn to teach. How do teaching assistants learn to handle disagreement among students? When does a tenured professor have a duty not to attack publicly a non-degreed teaching assistant? How should faculty respond when a colleague behaves in ways they dislike?

At the center of all these questions, however, is the question of conservatism and homosexuality. Not too long ago, opposition to gay marriage was a common part of our mainstream political discussion. These days, in college seminars, newspapers, technology companies, and public policy, any conservative notion that homosexuals do not have the right to marry one another is often considered rank bigotry.

Is it possible for conservative intellectuals to oppose gay marriage without being branded bigots? Has that culture-war train left the station?