and back to the stupid

Noticed on DailyKos a link to some trite political analysis by Charlie Cook, that concludes:

But resistance to Obama is making it close--just as a stool with only three of its legs can stand but is shaky. Whether the fourth leg is defined as whites over 50, working-class whites, or whites over 65, McCain's challenge this week is to firm up his grip and keep Obama from adding the final leg to the stool.

Never mind that 3-legged stools can be really stable, what concerns me most is the thought of McCain wanting Obama to have loose stool.