Given that everything the Chimp does is more about image than action, you would think the lump in his bed might have had the good sense to rein in the holiday overkill this year. Food banks all over the country are crying the empty blues, but it’s Excess Accomplished on Pennsylvania Avenue: shrimp and ham and steak and crab cakes and tamales and endless asparagus in December, and that’s even before the 18 desserts at each reception. Not surprisingly, even the menu lies — “creamed pan drippings” sounds to me an awful lot like good old “gravy.”