138 friends? Wow, the Brady Campaign isn't too popular.
The idea of politics on Myspace is, in my opinion, a failed concept. It's a social networking site for teenagers to act like teenagers (for better or for worse).
There are older users for whom having "Brady Campaign to Prevent Gun Violence" in your friends list isn't an automatic disqualifier to getting laid, but I'm betting they're largely outnumbered by younger people who don't give a rip.
Then again, I guess every little bit counts when you're talking exposure, and Myspace is cheaper than teevee commercials.