Discrimination and the Establishment Clause.
The University of California, Hastings College of the Law ("Hastings"), like other American law schools, has anon-discrimination policy that forbids discrimination on the basis of "race, color, religion, national origin, ancestry, disability, age, sex, or sexual orientation." Hastings applies this policy to its own admissions decisions and programs, as well as to student groups. As a condition of receiving official recognition--a prerequisite for access to certain law school facilities, and for eligibility for funding--student organizations must themselves adhere to the Hastings non-discrimination policy. As the policy is implemented, that means that student groups must admit as a member any student who wishes to join.
The anti-discrimination policy came into conflict with a policy of the Hastings branch of the Christian Legal Society ("CLS"), a student group that requires all of its members to pledge to uphold, among other things, "biblical principles of sexual morality." As interpreted by CLS, those principles forbid "unrepentant participation in or advocacy of a sexually immoral lifestyle." Although CLS contended in its successful petition for review to the Supreme Court that this policy forbids a variety of practices, including, for example, adultery, the controversy at Hastings, as at other law schools where the CLS has clashed with student-group recognition rules, concerns sexual orientation.
After Hastings withdrew funding for CLS based on its failure to abide by the non-discrimination policy, CLS sued. The law school prevailed in both the district court and the appeals court. Who wins in the Supreme Court will likely depend on how the Justices read two lines of First Amendment cases.