and Republican supporters of free silver formed the Silver Republican Party. Many of these, including Henry M. Teller and Fred Dubois, later joined the Democratic Party. 20th century Following Theodore Roosevelt's loss to William Howard Taft in the 1912 Republican Party presidential primaries, Roosevelt and his followers broke off from the Republican party to form the Bull Moose Party. Wisconsin senator Robert M. La Follette also launched a presidential bid under the Progressive Party in 1924 after both the Republican Party and Democratic Party nominated conservative candidates. A period of realignment commenced following the onset of the Great Depression, as President Franklin D. Roosevelt constructed the successful New Deal coalition. Over the ensuing decades, Roosevelt's Democrats embraced several tenets of modern American liberalism, while the Republican Party tended to favor conservatism. The transition into today's Democratic Party was cemented in 1948, when Harry Truman introduced a pro-civil rights platform and, in response, many Democrats walked out and formed the Dixiecrats. Most rejoined the Democrats over the next decade, but in the 1960s, Lyndon Johnson passed the Civil Rights Act and Voting Rights Act. The civil rights movement had also deepened existing racial tensions in much of the Southern United States, and Republican politicians developed strategies that successfully contributed to the political realignment of many white, conservative voters in the South who had traditionally supported the Democratic Party rather than the Republican Party. These approaches are known as the Southern strategy. Anti-civil rights members left the Democratic Party in droves, and Senator Strom Thurmond, the Dixiecrats' presidential candidate from 1948, joined the Republican Party. Notable party switchers Liberal Republican Robert La Follette, Sr. ran for president as the candidate of the Progressive Party in 1924, while remaining a Republican in the Senate. There have also been several instances of politicians continuing to be a member of a political party while running other campaigns as an independent. The most prominent examples include southern Democratic segregationists Strom Thurmond in 1948 and George Wallace in 1968, who remained in the Democratic Party for statewide campaigns but mounted national presidential campaigns as independents. Wallace later ran in the 1972 Democratic primaries. Senator Joseph Lieberman in 2006 ran for Senate in Connecticut under the party Connecticut for Lieberman, although still identifying as a Democrat. Other political figures, such as Ed Koch, Jim Leach, Zell Miller, Colin Powell, did not formally leave their parties, but supported a