I wondered about this, but I think we've come a really long way with technology in the last 15 years. Back then writing crap like this would have been a semi-niche thing, and not something I would have expected to be preserved forever. Flippin heck, thank goodness some of my misdemeanors haven't been recorded for posterity!
So I think give the lad a chance. He wrote some very unpleasant things, if he has learned better then good for him, and at least he has an insight on how to change which could actually be useful. Sometimes it's not that productive having a bunch of people on a committee who all have the same background and ethos.
Also, hmmm politicians - plenty who have done a lot worse than talk shit, I genuinely wonder how many would be left if all the ones who had done/said something questionable were sacked?