I immensely enjoyed your comment response appended to the Feingold post. If I read it correctly, it was not quite written in your usual voice, and that change was part of what made it so entertaining.
Do I have a different persona in the comments? Maybe so. I feel more casual writing on the comments pages and tend to dash things off without thinking so much. It's more like email or an in-person conversation.
But generally, on the front blog page, in the comments, and teaching, when the subject is constititutional law, I tend to shift around to different levels of observation. Sometimes I'm trying to convey how the judges put the argument on paper, just to translate difficult textual and doctrinal arguments for laypersons or law students. Sometimes I'm trying to locate the debate in a political context. And sometimes I just step back and speculate about what kind of a human being would think about things like that.
And even in speaking on these different levels, sometimes I adopt a sober tone that channels the judge (or legislator or litigant) and defends him as he would defend himself and sometimes I adopt the voice of that person's opponent restating his motivations in rough sarcasm. Sometimes when I'm teaching I just walk to the other side of the room to play the cynic -- a move that worked better when a room had a stage. (All the stages were ripped out in the last renovation -- for various political reasons.)
But maybe, for the blog, I should add a new "team member" over here that would just be my nastier, more cynical alter ego. Or maybe I should just put the text in red when I'm walking over to that side of the stage.