In general, freedom of association includes the right to be free from compelled association. In Wooley v. Maynard, 430 U.S. 705, 97 S. Ct. 1428, 51 L. Ed. 2d 752 (1977), and Abood v. Detroit Board of Education, 431 U.S. 209, 97 S. Ct. 1782, 52 L. Ed. 2d 261 (1977), the Court held that freedom of association is unconstitutionally burdened where the state requires an individual to support or espouse ideals or beliefs with which he or she disagrees. Similarly, in Keller v. State Bar, 496 U.S. 1, 110 S. Ct. 2228, 110 L. Ed. 2d 1 (1990), the Court held that mandatory state bar membership dues could not be used to further ideological causes with which some members might disagree, unless the state could show that the expenditures were incurred for the purpose of regulating the legal profession or improving the quality of legal service.
“It is a clear application of Freedom of Association.”
The problem is the Supreme Court decided to do away with that right in Christian Legal Society v. Martinez. Sounds like the only reason the university got tagged here is it discriminated in unevenly applying the requirements to some organizations but not others.