It's probably not that hard to figure out. There's IP traces, email addies posted, and those who probably know the posters and are able to figure out who they are from the style of writing or information there. Letters to the editor that match a post are key.
There are dozens of pols who lurk here, and I'm not surprised if some of them post. I know reporters are here, and I'd be shocked if dem and GOP stratigests aren't here from time to time.
Unless this site is giving up the IP's, that's not possible. The other stuff is just too circumstantial. If he's been in politics for 10 years, he knows better than to leave an email address. No, it has to be something else.