Near the end of a dime-a-dozen piece by John Leo about how liberal college faculty are in the new U.S. News and World Report college rankings issue, Leo makes a facinating statement: "Litigation is likely to play some role in reforming the campuses, particularly at state schools, where taxpayers are expected to foot the bill for ideological excesses. One suit successfully challenged the funding of leftist campus causes with fees collected from all students."
The case Leo is talking about came out of Wisconsin a few years back. Scott Southworth sued the University of Wisconsin over being forced to help fund so-called liberal student groups, and in 2000, the case was decided by the Supreme Court. However, he lost; the University of Wisconsin won. The suit wasn't successful (if winning is how Leo defines sucess, and I think he does). The 'leftist campus causes' are still funded by mandatory student fees. US News and World Report needs better editors reading Leo's pieces.
You can read the decision here: Board of Regents of the University of Wisconsin System v. Scott Southworth et. al. or look it up yourself at 529 U.S. 217. Don't bother, however, looking for a dissenting opinion -- it was a 9-0 vote.