The Party for Socialism and Liberation (PSL) is a communist party in the United States. PSL was established in 2004, when its members split from the Workers World Party. The group believes that a socialist revolution is necessary to overthrow capitalism and establish socialism. The organization works toward this end by organizing and participating in local protests, running candidates in elections, and political education favoring a revolutionary socialist vanguard party.

The Workers World Party (WWP) is a Marxist–Leninist communist party founded in 1959 by a group led by Sam Marcy. WWP members are sometimes called Marcyites. Marcy and his followers split from the Socialist Workers Party (SWP) in 1958 over a series of long-standing differences, among them their support for Henry A. Wallace's Progressive Party in 1948, their view of People's Republic of China as a workers' state, and their defense of the 1956 Soviet intervention in Hungary, some of which the SWP opposed.