By 1938 conservative Democrats in Congress—chiefly from the South—formed a coalition with Republicans that largely blocked liberal domestic policy until the 1960s. However, most of the conservative Southern Democrats supported the foreign policy of Roosevelt and Truman. Roosevelt tried to purge the more conservative Democrats in numerous states in 1938. He especially tried to unseat those up for reelection who defeated his plan to pack the Supreme Court in 1937. He failed in nearly all cases, with a major success in defeating John J. O'Connor in Manhattan, a spokesman for big business. A different source of conservative Democratic dissent against the New Deal came from a group of journalists who considered themselves classical liberals and Democrats of the old school, and were opposed to big government programs on principle; these included Albert Jay Nock and John T. Flynn, whose views later became influential in the libertarian movement. 1948–1968: Segregationist backlash The proclamation by President Harry S. Truman and Minneapolis Mayor Hubert Humphrey of support for a civil rights plank in the Democratic Party platform of 1948 led to a walkout of 35 delegates from Mississippi and Alabama. These southern delegations nominated their own States Rights Democratic Party, better known as the Dixiecrats, nominees with South Carolina Governor Strom Thurmond leading the ticket (Thurmond would later represent South Carolina in the U.S. Senate, and join the Republicans in 1964). The Dixiecrats held their convention in Birmingham, Alabama, where they nominated Thurmond for president and Fielding L. Wright, governor of Mississippi, for vice president. Dixiecrat leaders worked to have Thurmond-Wright declared the "official" Democratic Party ticket in Southern states. They succeeded in Alabama, Louisiana, Mississippi, and South Carolina; in other states, they were forced to run as a third-party ticket. Preston Parks, elected as a presidential elector for Truman in Tennessee, instead voted for the Thurmond-Wright ticket. Leander Perez attempted to keep the States Rights Party alive in Louisiana after 1948. Similar breakaway Southern Democratic candidates running on states' rights and segregationist platforms would continue in 1956 (T. Coleman Andrews), and 1960 (Harry F. Byrd). None would be as successful as the American Independent Party campaign of George Wallace, the Democratic governor of Alabama, in 1968. Wallace had briefly run in the Democratic primaries of 1964 against Lyndon Johnson, but dropped out of the race early. In 1968, he formed the new American Independent Party and received 13.5% of the popular vote,