neutralist an advocate of neutrality in international affairs
nullifier an advocate of nullification; someone who believes that a state can resist federal laws
drumbeater,
zealot,
partisan a member of an ancient Jewish sect in Judea in the first century who fought to the death against the Romans and who killed or persecuted Jews who collaborated with the Romans
secularist an advocate of secularism; someone who believes that religion should be excluded from government and education
separationist,
separatist an advocate of secession or separation from a larger group (such as an established church or a national union)
spokesperson,
interpreter,
representative,
voice an advocate who represents someone else's policy or purpose; "the meeting was attended by spokespersons for all the major organs of government"
suffragist an advocate of the extension of voting rights (especially to women)
