If you said you should play looser pre-flop than you normally would, I'd agree with you. But that doesn't mean you should be playing quite as loose as the riff-raff at the table. Often times, if a player sucks post-flop, it's an extension of the fact that he's a terrible player overall. He calls with garbage hands preflop and takes them way too far. It just won't be profitable to loosen up to the extent that you're playing even looser than this idiot.