Why did Boy Scouts of America v. Dale allow the Boy Scouts to exclude gay scoutmasters?

In Boy Scouts of America v. Dale (2000), the U.S. Supreme Court ruled that the Boy Scouts could exclude gay scoutmasters based on the First Amendment right to freedom of association.1

The Court held that forcing the organization to accept a gay scoutmaster would interfere with its expressive activity. Chief Justice William Rehnquist, writing for the majority, concluded that the presence of a gay scoutmaster would force the organization to send a message that it accepts homosexuality as a legitimate form of behavior, which conflicted with the group's stated values of being "morally straight" and "clean".1

While the state of New Jersey argued that its civil rights law prohibiting discrimination in public accommodations should prevail, the Court determined that courts should defer to a private organization's view regarding what might interfere with its constitutionally protected expression. Ethical principles regarding the balance between individual equality and the autonomy of private associations remain a subject of significant legal and moral debate.1