In the United States, the "one person, one vote" principle was established in a series of cases in the 1960s. Applying the Equal Protection Clause of the United States Constitution, the Supreme Court majority opinion in Reynolds v. Sims (1964) ruled that state legislatures needed to redistrict in order to have congressional districts with roughly equal represented populations. In addition, the court ruled that, unlike the United States Congress, both houses of state legislatures needed to have representation based on districts containing roughly equal populations, with redistricting as needed after censuses
Affirmative action in the United States is a set of laws, policies, guidelines, and administrative practices "intended to end and correct the effects of a specific form of discrimination." These include government-mandated, government-sanctioned, and voluntary private programs that tend to focus on access to education and employment, specifically granting special consideration to historically excluded groups such as racial minorities or women. The impetus toward affirmative action is redressing the disadvantagesassociated with past and present discrimination. Further impetus is a desire to ensure public institutions, such as universities, hospitals, and police forces, are more representative of the populations they serve.
The Immigration and Nationality Act of 1965 (H.R. 2580; Pub.L. 89–236, 79 Stat. 911, enacted June 30, 1968), also known as the Hart–Celler Act, changed the way quotas were allocated by ending the National Origins Formula that had been in place in the United States since the Emergency Quota Act of 1921. Representative Emanuel Celler of New York proposed the bill, Senator Philip Hart of Michigan co-sponsored it, and Senator Ted Kennedy of Massachusetts helped to promote it.