Origins of the American Civil War
In almost every northern state, organizers attempted to have a Republican Party or an anti-Nebraska fusion movement on ballots in 1854. In areas where the radical Republicans controlled the new organization, the comprehensive radical program became the party policy. Just as they helped organize the Republican Party in the summer of 1854, the radicals played an important role in the national organization of the party in 1856. Republican conventions in New York, Massachusetts, and Illinois adopted radical platforms. These radical platforms in such states as Wisconsin, Michigan, Maine, and Vermont usually called for the divorce of the government from slavery, the repeal of the Fugitive Slave Laws, and no more slave states, as did platforms in Pennsylvania, Minnesota, and Massachusetts when radical influence was high.
Party switching in the United States
Two progressive Republicans, Theodore Roosevelt and Robert M. La Follette Sr., launched strong third party presidential candidacies in the early 20th century, but neither founded a durable political party. 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.