Media Bias in the AP?

I know pointing out media bias is like shooting fish in a bottle, but I was reading this AP story about the protesters at the RNC, and saw that some were described as "peace activists" while others were described as "Republican Party activists". If anyone knows Alan Rybak, a real estate agent from Lakeville, Minn., please ask him if he is a paid full-time activist for the Republican Party. If not, then on what basis is he a "Republican Party activist." Because he holds up a sign that says "Support our Troops"? Did the author of this article, Amy Forliti, do some research and uncover his voting record as Republican? If voting for Republicans makes you an 'activist', how come the "peace activist" wasn't described as a "Democratic Party activist"? I know, I know- like shooting fish in a bottle.

UPDATE: Atlas Shrugs is doing yeoman's work on covering the protests. I agree with their assessment- The AP's pictures only the the police reacting to subdue the crowd, and not the crowd's sickening anti-social and criminal behavior. The slant is sick.