The only thing required for membership in the two major political parties is personal preference. Americans may choose to become a Republican or Democrat based on their beliefs and ideals.
In 2012, 24 percent of Americans described themselves as being Republicans and 32 percent were Democrats. The party with the fastest growing membership was the Independents, with 32 percent identifying with this party.
Race plays a major role in whether a person self-identifies as Republican or Democrat. In 2008, 32 percent of white Americans were Republicans and 26 percent were Democrats. More African Americans were members of the Democrat party, and 32 percent of Hispanics were Democrats.