Public concerns about communism were heightened by international events. In 1949, the Soviet Union successfully tested a nuclear bomb and communist forces led by Mao Zedong (1893-1976) took control of China. The following year saw the start of the Korean War (1950-53), which engaged U.S. troops in combat against the communist-supported forces of North Korea. The advances of communism around the world convinced many U.S. citizens that there was a real danger of “Reds” taking over their own country. Figures such as McCarthy and Hoover fanned the flames of fear by wildly exaggerating that possibility.
As the Red Scare intensified, its political climate turned increasingly conservative. Elected officials from both major parties sought to portray themselves as staunch anticommunists, and few people dared to criticize the questionable tactics used to persecute suspected radicals. Membership in leftist groups dropped as it became clear that such associations could lead to serious consequences, and dissenting voices from the left side of the political spectrum fell silent on a range of important issues. In judicial affairs, for example, support for free speech and other civil liberties eroded significantly. This trend was symbolized by the 1951 U.S. Supreme Court ruling in Dennis v. United States, which said that the free-speech rights of accused Communists could be restricted because their actions presented a clear and present danger to the government.
Americans also felt the effects of the Red Scare on a personal level, and thousands of alleged communist sympathizers saw their lives disrupted. They were hounded by law enforcement, alienated from friends and family and fired from their jobs. While a small number of the accused may have been aspiring revolutionaries, most others were the victims of false allegations or had done nothing more than exercise their democratic right to join a political party.
Though the climate of fear and repression began to ease in the late 1950s, the Red Scare has continued to influence political debate in the decades since. It is often cited as an example of how unfounded fears can compromise civil liberties.