I have a certain amount of sympathy for politicians on Twitter... if they don't engage then it's pointless them being there (imho), but if they do engage (without consulting a team of PR experts each time) then they run the risk of posting something half-thought-through that can lead to a massive media fuss and even them losing their position - not always fairly, I don't think. I'd rather they were free to be people, imperfections and all, than that they had to self-censor so much. Maybe he just thought better of the discussion after he'd stepped away from it, and decided he didn't want snippy messages on his profile for new visitors to see. Deletion isn't deletion these days, but it's still a fairly effective first line of correction. By the way, apparently I can't post a comment here unless I enable third-party cookies - it just gets invisibly /dev/null'd :- I don't think that used to be the case, although I can't remember for certain.