The formation of the New Deal coalition has been the subject of much scholarly discussion, as have the theories of voting behaviour which have informed that discussion. This essay seeks to investigate both the history and the theory. First, it analyses the timing and mechanics of the participation of Philadelphia's Italian-Americans in the Roosevelt coalition. Italian-Americans were a key component of the Democratic majority nationwide, and as pre-New Deal Republican bailiwicks that began to turn Democratic in the 1930s, Pennsylvania and Philadelphia are ideal settings to study the forging of the Roosevelt coalition not only on the federal but also on the state and local level. Secondly, the essay tests some hypotheses about the New Deal realignment. It suggests that none of the standard hypotheses convincingly explains what was happening in Philadelphia's Italian-American community in the 1930s and 1940s.