Jack Breckinridge Tenney (April 1, 1898 – November 4, 1970) was an American politician who was noted for leading anti-communist investigations in California in the 1940s and early 1950s as head of the California Senate Factfinding Subcommittee on Un-American Activities ("Tenney Committee"); earlier, he was a song-composer, best known for "Mexicali Rose".

[1] Upon his return, he married Leda Westrem, a 16 year-old stenographer, and they had a baby while living at 3764 South Main street, Los Angeles.

Marital problems ensued when Tenney became a professional musician in 1919, formed the Majestic Orchestra and spent 1920 to 1923 playing dance halls and hotels in Calexico and Mexicali.

[5] However, Tenney turned his energies towards night law school, and moved back to Los Angeles in 1928.

[6] Those investigated by Tenney's committee included: In 1941, producer Walt Disney took out an ad in Variety, the industry trade magazine, declaring his conviction that "Communist agitation" was behind a cartoonists and animators' strike.

According to historians Larry Ceplair and Steven Englund, "In actuality, the strike had resulted from Disney's overbearing paternalism, high-handedness, and insensitivity."

[13] In 1941, John D. Henderson, President of the California Library Association (CLA), predicted that in the 1940s librarians would experience a "war on books and ideas."

At the same time, Tenney was appointed the chair of a legislative Fact-Finding Committee on Un American Activities in California, which was charged with investigating "all facts ... rendering the people of the State ... less fit physically, mentally, morally, economically, or socially.

"[14] The Tenney Committee began to investigate any textbooks associated with suspected subversives, such as Carey McWilliams or Langston Hughes.

Committee member Richard E. Combs argued that the series put "undue emphasis on slums, discrimination, unfair labor practices, ... and a great many other elements that comprise the seedy side of life.

The conduct of the hearings, by a later account, "egregiously violated due process",[21] and of the hundreds of people subpoenaed and interrogated in its eight years, not a single one had been indicted, much less convicted, of any sort of subversion.

[21] In 1952, Tenney sought to move to the United States House of Representatives, accepting the help of anti-Semite Gerald L. K. Smith of the America First Party.

[23][24] Tenney ran for Vice President on the 1952 Christian National Party ticket headed by Douglas MacArthur.