It's a fact, documented by two recent studies, that registered Republicans and self-proclaimed conservatives make up only a small minority of professors at elite universities. But what should we conclude from that?

Conservatives see it as compelling evidence of liberal bias in university hiring and promotion. And they say that new "academic freedom" laws will simply mitigate the effects of that bias, promoting a diversity of views. But a closer look both at the universities and at the motives of those who would police them suggests a quite different story.

Claims that liberal bias keeps conservatives off college faculties almost always focus on the humanities and social sciences, where judgments about what constitutes good scholarship can seem subjective to an outsider. But studies that find registered Republicans in the minority at elite universities show that Republicans are almost as rare in hard sciences like physics and in engineering departments as in softer fields. Why?

One answer is self-selection - the same sort of self-selection that leads Republicans to outnumber Democrats four to one in the military. The sort of person who prefers an academic career to the private sector is likely to be somewhat more liberal than average, even in engineering.

But there's also, crucially, a values issue. In the 1970's, even Democrats like Daniel Patrick Moynihan conceded that the Republican Party was the "party of ideas." Today, even Republicans like Representative Chris Shays concede that it has become the "party of theocracy."

Consider the statements of Dennis Baxley, a Florida legislator who has sponsored a bill that - like similar bills introduced in almost a dozen states - would give students who think that their conservative views aren't respected the right to sue their professors. Mr. Baxley says that he is taking on "leftists" struggling against "mainstream society," professors who act as "dictators" and turn the classroom into a "totalitarian niche." His prime example of academic totalitarianism? When professors say that evolution is a fact.

In its April Fools' Day issue, Scientific American published a spoof editorial in which it apologized for endorsing the theory of evolution just because it's "the unifying concept for all of biology and one of the greatest scientific ideas of all time," saying that "as editors, we had no business being persuaded by mountains of evidence." And it conceded that it had succumbed "to the easy mistake of thinking that scientists understand their fields better than, say, U.S. senators or best-selling novelists do."

The editorial was titled "O.K., We Give Up." But it could just as well have been called "Why So Few Scientists Are Republicans These Days." Thirty years ago, attacks on science came mostly from the left; these days, they come overwhelmingly from the right, and have the backing of leading Republicans.

Scientific American may think that evolution is supported by mountains of evidence, but President Bush declares that "the jury is still out." Senator James Inhofe dismisses the vast body of research supporting the scientific consensus on climate change as a "gigantic hoax." And conservative pundits like George Will write approvingly about Michael Crichton's anti-environmentalist fantasies.

Think of the message this sends: today's Republican Party - increasingly dominated by people who believe truth should be determined by revelation, not research - doesn't respect science, or scholarship in general. It shouldn't be surprising that scholars have returned the favor by losing respect for the Republican Party.

Conservatives should be worried by the alienation of the universities; they should at least wonder if some of the fault lies not in the professors, but in themselves. Instead, they're seeking a Lysenkoist solution that would have politics determine courses' content.

And it wouldn't just be a matter of demanding that historians play down the role of slavery in early America, or that economists give the macroeconomic theories of Friedrich Hayek as much respect as those of John Maynard Keynes. Soon, biology professors who don't give creationism equal time with evolution and geology professors who dismiss the view that the Earth is only 6,000 years old might face lawsuits.

If it got that far, universities would probably find ways to cope - by, say, requiring that all entering students sign waivers. But political pressure will nonetheless have a chilling effect on scholarship. And that, of course, is its purpose.