In United States politics, modern liberalism, a form of social liberalism, is one of two current major political ideologies. It combines ideas of civil liberty and equality with support for social justice. Economically, modern liberalism supports government regulation on private industry, opposes corporate monopolies, and supports labor rights. Its fiscal policy opposes any reduction in spending on the 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, increasing diversity, expanding access to education and healthcare, regulating economic activity, and environmentalism. 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 Infrastructure Investment and Jobs Act.

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 Congress from 1937 until the Johnson administration. After World War Two, northern Democrats began to support 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 adopted conservatism at the party's main ideology. As a group, "liberals" are referred to as left or center-left and "conservatives" as right or center-right. Starting in the 21st century, there has also been a sharp division between liberals who tend to live in denser, more heterogeneous urban areas and conservatives who tend to live in less dense, more homogeneous rural communities, with suburban areas largely split between the two. Since the 2000 election, blue and red have been the party colors of the Democrats and Republicans respectively, in contrast to the use of blue for conservatism and red for leftism in the rest of the Western world. (Full article...)

Thomas Hill Green (7 April 1836 – 26 March 1882), known as T. H. Green, was an English philosopher, political radical and temperance reformer, and a member of the British idealism movement. Like all the British idealists, Green was influenced by the metaphysical historicism of G. W. F. Hegel. He was one of the thinkers behind the philosophy of social liberalism. (Full article...)