Below is a quick chart showing the extent to which each pollster has tended to favor one candidate or another so far in the primaries. This is determined by comparing the pollster’s final survey in each state against the average of other pollsters who surveyed that state. So, for example, if Zogby expects Obama win a state by 10 points, and the other polls suggest that he will win by 8 points, that rates as a +2 for Zogby in that contest. A pollster is listed if they’ve surveyed at least five Democratic caucuses and primaries to date.
Zogby Obama +4.6
Strategic Vision Obama +3.3
PPP Obama +2.7
Quinnipiac Obama +1.6
Rasmussen Obama +0.8
Suffolk Obama +0.2
SurveyUSA Clinton +0.8
Research 2000 Clinton +1.4
Mason-Dixon Clinton +2.0
Insider Advantage Clinton +2.1
ARG Clinton +4.5
So, if you think that ARG polls always look good for Clinton, or Zogby polls always look good for Obama, it is not your imagination. It is also not a coincidence that most of the stronger pollsters don’t seem to show a substantial leaning one way or the other.