Why McCarthy suddenly changed parties was never explained, but prospects for ambitious Wisconsin politicians were dim inside the poorly organized Democratic party, for most [[New Deal]]ers supported the state's [[Progressive party#LaFollete creates a third party in 1924|Progressive party]]. During the war, however, that party collapsed, torn apart between its [[New Deal]] domestic liberalism, and its intensely isolationist opposition to Roosevelt's foreign policy. Increasingly out of touch with Wisconsin, its leader [[Robert LaFollette]] looked to his family's past glories and made the blunder of trying for reelection to the Senate in 1946 as a Republican. | Why McCarthy suddenly changed parties was never explained, but prospects for ambitious Wisconsin politicians were dim inside the poorly organized Democratic party, for most [[New Deal]]ers supported the state's [[Progressive party#LaFollete creates a third party in 1924|Progressive party]]. During the war, however, that party collapsed, torn apart between its [[New Deal]] domestic liberalism, and its intensely isolationist opposition to Roosevelt's foreign policy. Increasingly out of touch with Wisconsin, its leader [[Robert LaFollette]] looked to his family's past glories and made the blunder of trying for reelection to the Senate in 1946 as a Republican. |