The conservative coalition, in the United States, was an unofficial Congressional coalition bringing together the conservative majority of the Republican Party and the conservative, mostly Southern, minority of the Democratic Party.
Aside from 1949 to 1951, it controlled the United States Congress from 1939 to 1961 and remained a potent force until the mid-1980s.
In 1936, President Franklin D. Roosevelt had won a second term in a landslide, sweeping all but two states over his Republican opponent, Alf Landon. For the 1937 session of Congress the Republicans would have only 17 Senators (out of 96 total) and 89 congressmen (out of a total of 431). Given his party's overwhelming majorities, Roosevelt decided he could overcome opposition to his liberal New Deal policies by the conservative justices of the U.S. Supreme Court, which had struck down many New Deal agencies as unconstitutional. Roosevelt proposed to expand the size of the court from nine to fifteen justices; he could then "pack" the court with six new justices who would support his policies.
However, many conservative Southern Democrats strongly opposed the plan. Among their leaders were Senators Harry Byrd and Carter Glass of Virginia and Vice-President John Nance Garner of Texas. U.S. Senator Josiah Bailey (D-NC) released a "Conservative Manifesto" in December 1937. "Give enterprise a chance, and I will give you the guarantees of a happy and prosperous America," Bailey said. The document called for a balanced federal budget, state's rights, and an end to labor union violence and coercion. Over 100,000 copies were distributed and it marked a turning point in terms of congressional support for New Deal legislation.
Democratic opposition to Roosevelt's "court packing" Judiciary Reorganization Bill of 1937 was first led by coalition Democrat and House Judiciary Committee chairman Hatton W. Sumners. Sumners refused to endorse the bill, actively chopping it up within his committee in order to block the bill's chief effect of Supreme Court expansion. Finding such stiff opposition within the House, the administration arranged for the bill to be taken up in the Senate. Congressional Republicans decided to remain silent on the matter, denying pro-bill congressional Democrats the opportunity to use them as a unifying force. Republicans then watched from the sidelines as their Democratic coalition allies split the Democratic party vote in the Senate, defeating the bill. In the 1938 congressional elections the Republicans scored major gains in both houses, picking up six Senate seats and 80 House seats. Thereafter the Southern Democrats and Republicans in both Houses of Congress would often vote together on major economic issues, thus defeating many proposals by liberal Democrats. Truman's Fair Deal was passed during a brief period of liberal control in 1949–51.