Conservatism and liberalism are the two biggest ideologies in the United States. Conservatism as we know it today first began to thrive in the second half of the 20th century as a response to widespread social change in the US, such as the Great Depression, World War II, and the civil rights movement. Though there are various differences between the various ideological groups who belong to the Conservative movement, Conservatives generally support tax cuts and less government interference: a laissez-faire system. Approximately one-third of the American public identifies as Conservative, and this faction tends to vote for the Republican party. Many, but not all, oppose abortion, same-sex marriage, and gun control laws.

Liberalism in the US is much more progressive than Conservatism. Liberals tend to advocate for strong laws which defend civil liberties. They call for changes to be brought to society which better the lives of marginalized people. They generally take an opposite stance to Conservatives, calling for abortion rights, marriage equality, and stricter gun control. Liberals generally reject laissez-faire government ideas and embrace a mixed system, where the government intervenes subtly in some areas of society. Approximately 19-26% of the American public is thought to identify as a liberal, and Liberals consist of almost 50% of the base of the Democratic Party.