I'm speechless over the cynicism at work here.
If you listen to Obama's full remarks you'll discover a) that Obama not only didn't mention Palin in the runup to this comment, he had specifically referred to John McCain and b) that he used multiple metaphors, indicating he was casting about to make a general point and not targeting Palin. Obama immediately went on to add "You can wrap an old fish in a piece of paper called change. It's still gonna stink."
Maybe Obama was calling Palin, whom he never named, both a pig and a rotten fish. Or maybe Republicans are playing identity politics cynically enough to make Al Sharpton cringe.