That's because FR is a conservative forum and Rudy ain't conservative. Supporters of all of the other guys were free to post whatever they liked. Even us Paultards are tolerated.
They weren't booted for supporting Rudy, many Rudy supporters are still around. The ones that where booted (and that thread is still available) where acting like a**holes, asking for it. I am surprised how much patience the mods have, they kept warning them over and over and gave them second, third, and fourth chances.