There are any number of polling sites around the net covering the presidential campaign. David Moore lists some of the more popular ones. Who’s David Moore?
David Moore, author of The Opinion Makers: An Insider Reveals the Truth Behind the Polls, is a former Vice President of the Gallup Organization and Managing Editor of the Gallup Poll.
Not in Moore’s list, but mentioned in comments, are two sites that are to my mind the most interesting, FiveThirtyEight.com, run by sabermetrician Nate Silver, and Sam Wang’s Princeton Meta-Analysis.
I won’t go into detail here; there’s plenty of information at the two sites. If you’re a poll-follower, though, check them both out. (There’s something of a rivalry between the two; Robert at Angry Bear has a starting point for the discussion.
This graphic is from the Princeton site.
