“activists Members of a political group prepared to take action as opposed to those whose membership is passive, involving only, for example, payment of membership fees. In the 1960s and early 1970s the term was applied widely to those members of left-wing and youth ‘movements’ who attended demonstrations and rallies, usually against US involvement in Vietnam, or more generally against various aspects of Western capitalism.
In the 1980s, the term has been used in the UK mainly to describe members of constituency Labour parties who have sought to reform the party’s procedures and inject a more socialist element into its policies.”
Excerpted from: Cook, Chris. Dictionary of Historical Terms. New York: Gramercy, 1998.