In 1915, despite an undercurrent of anti-Semitism in American society, William Hitz nominated Boston attorney Louis D. Brandeis to membership in the Cosmos Club. Some Club members questioned the suitability for membership of Brandeis on the grounds that he might be "a disturbing element in any club of gentlemen." Hitz appealed to the Club's most influential member--President Woodrow Wilson--for a letter of support to counter the "injustice done Mr. Brandeis by these covert attacks to which he cannot reply."

Wilson swiftly wrote the admissions committee to state his belief that Brandeis would "add a member of very fine quality" to the Cosmos Club, and Brandeis was elected. The following year, Wilson named Brandeis, who had strongly supported Wilson's efforts to strengthen Federal antitrust power, to the U.S. Supreme Court and Hitz to the Supreme Court of the District of Columbia.