Modern political science has questioned whether average citizens have sufficient political information to cast meaningful votes. A series of studies coming out of the University of Michigan in the 1950s and 1960s argued that voters lack a basic understanding of current issues, the liberal-conservative ideological dimension, and the relative ideologic Dilemma.

The National Voting Rights Act of 1965 (42 U.S.C. § 1973–1973aa-6) outlawed discriminatory voting practices that had been responsible for the widespread disenfranchisement of African Americans in the United States. Echoing the language of the 15th Amendment, the Act prohibited states from imposing any "voting qualification or prerequisite to voting, or standard, practice, or procedure ... to deny or abridge the right of any citizen of the United States to vote on account of race or color." Specifically, Congress intended the Act to outlaw the practice of requiring otherwise qualified voters to pass literacy tests in order to register to vote, a principal means by which southern states had prevented African-Americans from exercising the franchise.

The Act established extensive federal oversight of elections administration, providing that states with a history of discriminatory voting practices (so-called "covered jurisdictions") could not implement any change affecting voting without first obtaining the approval of the Department of Justice, a process known as pre-clearance. These enforcement provisions applied to states and political subdivisions (mostly in the South) that had used a "device" to limit voting and in which less than 50 percent of the population was registered to vote in 1964. Congress has amended and extended the Act several times since its original passage, the most recent being the 25-year extension signed by President George W. Bush on July 27, 2006.