The Ku Klux Klan in the early 20th century opposed school choice as part of its overall white-supremacist stance. Its method of choice for fighting it was supporting compulsory public education, seeing it as a means of "Americanizing 'Un-American' foreigners."
The Klan's anti-Catholicism led to its support of the controversial Oregon Compulsory Education Act of 1922. The bill sought to close Catholic schools in the state and force students to attend public schools, thus limiting "the amount of 'non-Protestant' instruction they received," a University of Washington history says. The law was struck down by the Supreme Court in 1925.