Early political uses of red refer to revolutionary social movements before it became associated with adherents of Marxism-Leninism and Communism, as well as with the former Soviet Union. Besides the Soviet Red Army, formed in the aftermath of the Russian Revolution of 1917, there was the extreme left-wing terrorist organization the Italian Red Brigades, which was active during the 1970s and whose objective was to pave the way for a Marxist upheaval. During the 1960s, the Red Guards were organized by Chinese leader Mao Tse-tung to revitalize the revolutionary spirit of the Communist Party.
Another use of red is in American politics, where it indicates that one supports Republican candidates or their policies. The term red state, for example, gained popularity during the 2000 U.S. presidential election between Republican George W. Bush and Democrat Al Gore. News coverage showed election results with a two-tone map. A red state meant it was won by the Republican candidate and a blue state meant it was won by the Democrat. That election gave momentum to the political use of both colors.
The pundits, the pundits like to slice and dice our country into red states and blue states. Red states for Republicans, blue states for Democrats.
— Barack Obama, speech, 27 July 2004