This site needs an auto-moderator. It would be relatively easy to design software to detect and block the sort of activity that was going on here while the moderators were away.
Word recognition software would work in this guy's case.
My son moderates a forum for his friends and he uses word recognition blockers.
This spammer is so predictable he'd be easy to block. A "political" spammer would not be so easy to block on a political site, but this guy's just into obscene stuff.