Fifty-one years ago, when liberalism and social welfare democracy were expanding in all advanced industrialized nations, V.O. Key, Jr., forecast the decline of postwar liberalism in the United States. Current discussion of the decline of liberalism has ignored Key or, when evidence is lacking, has incorrectly cited him. In contrast to Key's relatively direct, simple, and heavily documented reasoning, current explanations are multifactorial, complex, less well documented, and often ideologically loaded. Some explanations for the “postwar” decline identify causal factors more than six years after the war, yet they ignore events in 1945–47. At the fifty-first anniversary of V.O. Key's Southern Politics in State and Nation, attention to Key's forecast and Occam's razor is called for. Key argued that racism in the South, exerted through congressional committees, would lead to a decline of liberalism in the nation. Using “legislative histories,” this article compares Key's single-factor “racial” explanation with a two-factor explanation—and by implication with multifactor ones—and finds Key's more compelling and parsimonious. Archival sources indicate that more than two years before the 1948 Democratic Convention, Charlie Ross, Truman's closest advisor, and Truman himself encouraged Key to assess the emerging postwar politics of the South. As Key anticipated, institutionalized racism sunk the Fair Deal and postwar social democracy, despite Truman's efforts. The effects of racism on postwar and current politics and public administration should be reexamined as a key to understanding American distinctiveness or exceptionalism.