- FiveThirtyEight, now relocated to the NY Times.This is actually a nonpartisan blog dedicated to poll analysis.
- Paul Krugman, Nobel Prize-winning economist; read his columns on M & F as well
- Brad DeLong, economic historian at UC Berkeley
- Electoral-Vote, where the Votemaster is an expat US citizen living in Holland
There are plenty more out there: Daily Kos, etc.