In the case of Nixon v. Condon et al., 1931, the U.S. Supreme Court ruled that a Texas law allowing only white citizens to vote in Democratic primary elections was unconstitutional. The court held that by authorizing a discriminatory system, the state violated equal protection rights under the Fourteenth Amendment of African American voters who were denied participation in selecting candidates for public office. This decision overturned an earlier ruling (Nixon v Herndon) where it had been decided that political parties could set their own rules for primaries and thus exclude black voters if they chose to do so.

In the dissenting opinion for Nixon v. Condon, Justice Holmes argued that Texas' law allowing political parties to determine their own membership did not violate the Fourteenth or Fifteenth Amendments. He reasoned that a political party is a voluntary association and should have the right to decide its own rules of membership, including racial exclusions if it so chooses. Furthermore, he contended that voting in primary elections was not a constitutional right but rather an internal matter of each individual party's governance structure. Therefore, according to his view, state laws regulating such matters do not infringe upon any federally protected rights.