A more thorough explanation:

Overview: Boy Scouts of America et al. v. Dale (2000) is a Supreme Court case that dealt with the right to freedom of association under the First Amendment. This case established expressive association as an important First Amendment right. However, many civil rights organizations saw this as a setback for LGBTQ rights in America.

Background: James Dale was an Eagle Scout member of the Boy Scouts of America (BSA). BSA revoked Dale's membership when they found out he was gay, stating that BSA's values conflicted with Dale's homosexual activity. Dale sued BSA in New Jersey Superior Court, alleging discrimination on the basis of sexual orientation under New Jersey's public accommodations statute. The State Court ruled in favor of Dale, and the New Jersey Supreme Court affirmed. The Supreme Court, upon a writ of certiorari, reversed the lower court, holding that BSA had the freedom to express its views under the First Amendment and forcing BSA to admit certain members may impose on that freedom (particularly freedom of association).

Example: A private club that only allows members who are of a certain religion or political affiliation is protected under the First Amendment's freedom of association. They cannot be forced to accept members whose beliefs conflict with the organization's beliefs.

Explanation: This example illustrates the concept of freedom of association. Private organizations have the right to choose their members based on their beliefs and values. The Boy Scouts of America v. Dale case established that private organizations have the right to exclude members whose beliefs conflict with the organization's beliefs, even if it is based on sexual orientation.