Last week Pew put out a new report related to polling in the 2008 election. A couple findings I thought were particularly interesting:
-On state level Presidential polls the average error for live interviewers was 1.6%. For IVR polls it was 1.5%. On all state level polls the average error for live interviewers was 2.1% and for IVR it was 1.7%. The difference between live interviewer and automated outfits is not large, but the automated ones were slightly more accurate. It's just another piece of evidence that as much as some in the mainstream media might want to deny it, automated polls are just as good- or maybe even better- at calling the horse race than traditional ones.
-The other interesting finding was that on state level Presidential polls with some error, 74 out of 126 of them overestimated John McCain. And on all polls 125 out of 211 overestimated the Republican candidate. For all the accusations from the right of pollsters being biased toward Democrats, the data doesn't back up that assertion.