There's 538, a blog that uses all the polls - seriously, all of them - as the input to a predictive model. It's from the good folks behind Baseball Prospectus, and they bring that level of wonkery and that level of accuracy to the political realm. (Note - they are one of the very few who predicted, before the season began, that Tampa Bay would make the playoffs.) Mudflats, a progressive Alaska blog (wonder why that's there?) has been added. (In all seriousness, I would totally move to Alaska.) Finally, Balloon Juice, the blog of former Republican/still conservative/Obama supporter John Cole is back again.
Give em all a try!