Modern liberalism in the United States

Modern liberalism, often referred to simply as liberalism, is the dominant version of liberalism in the United States. It is most synonymous with the ideology known as social liberalism in much of the world, but is also known to combine elements of cultural liberalism, progressivism, civil liberty and social equality with support for social justice and a mixed economy. Modern liberalism is one of two major political ideologies in the United States, with the other being conservatism. Writing in 1993, American academic writer Ian Adams argued all major U.S. parties up to that point were "liberal and always have been. Essentially they espouse classical liberalism, that is a form of democratized Whig constitutionalism plus the free market. The point of difference comes with the influence of social liberalism."

Economically, modern liberalism accepts a role for government to protect against market failures, protect competition, and prevent corporate monopolies, and supports labor rights. Its fiscal policy supports sufficient funding for a social safety net, while simultaneously promoting income-proportional tax reform policies to reduce deficits. It calls for active government involvement in other social and economic matters such as reducing economic inequality, expanding access to education and healthcare, and protection of the shared natural environment, in large part on the contention that advances in those areas create a thriving economy in the long run. Modern liberalism was formed in the 20th century in response to the Great Depression. Major examples of modern liberal policy programs include the New Deal, the Fair Deal, the New Frontier, the Great Society, the Affordable Care Act, and the Build Back Better Plan.

In the first half of the 20th century, both major American parties shared influential conservative and liberal wings. The conservative northern Republicans and Southern Democrats formed the conservative coalition, which dominated the U.S. Congress from 1937 until the Johnson administration. Beginning in the Great Depression era, northern Democrats increasingly supported civil rights and organized labor, while voters and politicians in the formerly Solid South opposed them from within the Democratic Party. Following the passage of the Civil Rights Act of 1964, conservative Democrats began an exodus from the party, and supported Republican candidate Richard Nixon in 1968. By the 1970s, the Democratic Party became predominately liberal, and the Republican Party became predominately conservative.

In the 21st century, urban areas have become more liberal, and rural areas have become conservative. Since the 2000 election, blue and red have been the party colors of the Democrats and Republicans respectively; this is in contrast to the historical use of red when representing socialism and communism, e.g. the “Red Scare”.