A person with considerable experience in protesting who is often willing and able to put themselves in sometimes compromising positions in which others are not. Usually highly knowledgeable of the issues surrounding the protest and dedicated to the cause. Often a veteran of many protests and demonstrations and usually well-equipped to ensure that things run according to plan.
That protest camp is so well run, they must be professional protesters
Any unemployed, fanatically Liberal protester, who spends an inordinate amount of time protesting the Republican wing. Often protests so frequently, they lose track of what they are actually protesting. Usually falls within the age range of 18-35. Descriptions include bad dye jobs, nasty facial piercings, and copious amounts of tacky tattoos. While adopting a "hippy-ish" style dresscode, and associated hygiene practices.
"Berkeley University in California, produces the highest number of professional protesters, in all United States."