activist
• supporter of activism, one who advocates active involvement as a means to achieve political or other goals
• an activist is someone who does things to bring about political or social changes.
civil rights activist
• one who works toward the procuring and protection of civil liberties
cyber activist
• political activist who uses email and other tools of the internet in an effort to affect political change
gay rights activist
• person who works to further the rights of homosexuals
human rights activist
• person who actively supports the cause of human rights
leading activist
• one of the leaders of a political group, head of an activist organization
leftist activist
• supporter of liberal politics
political activist
• one who is active in the political arena in general or with a particular political party in particular
public activist
• social activist, one who is involved in public affairs, politician