Cold War anxiety reached new heights, or depths, during the Korean War and had a profound effect on American society. Conservatism outpaced reform. The process began early in World War II, when Roosevelt himself announced that "Dr. New Deal" had been replaced by "Dr. Win the War." The reform era was over, replaced by the inevitable conservative reaction of war, mirroring the World War I experience. War and Cold War provided an opportunity that conservative elites, alarmed by the specter of creeping socialism in the New Deal, would not let pass. The profitable matrix revolving around science, business, government, and defense cemented military Keynesianism over government spending on domestic concerns. While federal dollars fueled Cold War militarization, spending on social programs, deemed socialistic by many conservatives, would be contained at home. An inveterate New Dealer, Henry Wallace, launched a last-gasp campaign against the new order but was thoroughly repudiated in the 1948 election. Truman's stunning upset victory over Thomas Dewey underscored that containment, anticommunism, and militarization would illuminate the path to electoral triumph.
Hysteria over domestic communism brought repression and exercised a lasting chilling effect on left-wing sentiment. Beginning with the "Hollywood Ten" in 1946, former communists and left-wing sympathizers were harassed, purged, and put on notice. In 1950 the Alger Hiss case, in which a former high-level State Department diplomat was convicted of perjury for lying about being a communist agent, put liberals and former New Dealers on the defensive while giving rise to a new breed of politician, best embodied by Richard Nixon, for whom the Cold War provided the core of their identity. Federal Bureau of Investigation director J. Edgar Hoover—accountable to no one and since World War I obsessed with destroying radicalism—launched a campaign against thousands of Americans who had harbored left-wing sentiments. Despite the extraordinarily crude and reckless tactics of Joseph McCarthy, the junior senator from Wisconsin conducted a four-year campaign against thousands of alleged subversives. The victims of the postwar hysteria were not only the tens of thousands of men and women harassed by McCarthy and the FBI, but the basic constitutional rights of freedom of thought and association as well.