So in the latest daily tracking poll by Zogby, McCain has for the first time surged ahead to a 5 point lead. However, and you won't see this emphasized in the breathless stories trumpeting this news (how the media loves a good horse race!), the poll only included so-called "likely voters".
What are the exact criteria Zogby uses to determine "likely voters"? Who gets excluded? Groups like Blacks and those aged 18-29, who historically have a low turn-out but who voted in record numbers in the Democratic primaries? I'll see what I can find online.