A major political party in the USA. The present Republican Party was formed in 1854, being precipitated by the Kansas–Nebraska Act and by the agitation of the Free Soil Party; it brought together groups opposed to slavery but supporting a protective trade tariff. The party won its first presidential election with Abraham Lincoln in 1860 and from then until 1932 lost only four such contests, two each to Cleveland and Woodrow Wilson. Under more recent Republican Presidents Nixon, Ford, and Reagan, it became associated with military spending and a forceful assertion of US presence worldwide, especially in Central America. Strongly backed by corporate business, it nevertheless failed to maintain a grip on Congress, which usually had a Democratic majority even when the President was Republican. However, this trend was reversed in 1994, when the Republicans gained control of both the Senate and the House of Representatives for the first time in 40 years. Other important influences on the Republican Party in recent years have been the social and political conservatism of Christian fundamentalists and the radical ideas of Neoconservatism. Both were prominent in the presidency of George W. Bush. Since 2009 the Republican Party has been influenced by the Tea Party Movement. The maverick party-outsider, Donald Trump, won the 2016 presidential nomination and the subsequent election; the party also controlled both Houses in Congress. Trump was impeached in 2019 on charges of abuse of power and obstruction of justice but was acquitted.

Following a contentious election in November 2020, despite many recounts demanded by Trump, Joe Biden (with Kamala Harris as Vice-President) and the Democratic Party were successful, with Biden inaugurated as the 46th president in January 2021. Trump was impeached a second time in 2021, a week before he left office.