The Court considers only whether a public institution’s conditioning access to a student-organization forum on compliance with an all-comers policy violates the Constitution. CLS urges the Court to review, instead, the Nondiscrimination Policy as written—prohibiting discrimination on enumerated bases, including religion and sexual orientation. The policy’s written terms, CLS contends, target solely those groups that organize around religious beliefs or that disapprove of particular sexual behavior, and leave other associations free to limit membership to persons committed to the group’s ideology. This argument flatly contradicts the joint stipulation of facts the parties submitted at the summary-judgment stage, which specified: “Hastings requires that [RSOs] allow any student to participate, . . . regardless of [her] status or beliefs. For example, the Hastings Democratic Caucus cannot bar students holding Republican political beliefs. . . .” This Court has long recognized that parties are bound by, and cannot contradict, their stipulations... The Court therefore rejects CLS’s attempt to escape from the stipulation and shift its target to Hastings’ policy as written.