rule.

"One man, one vote" (or "one person, one vote&quot is a slogan that has been used in many parts of the world where campaigns have arisen for universal suffrage. During the 20th-century period of decolonisation and the struggles for national sovereignty, from the late 1940s onwards this phrase became widely used in less developed countries where majority populations were seeking to gain political power in proportion to their numbers.

The phrase was used in this form in an important legal ruling in the United States related to voting rights; applying the Equal Protection Clause of the US 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 both houses of state legislatures needed to have representation based on districts containing roughly equal populations, with redistricting as needed after censuses.[1] Many urban areas of the United States had been long underrepresented in Congress and state legislatures due to the failure of the latter to redistrict according to population.