There are a couple of really interesting things in this poll:
First, I am struck by how similar the “least likely” caucus goers in Iowa seem to break along roughly the same lines as national polls. Would anyone bat an eyelash at a national poll showing Clinton 33%, Obama 25%, Edwards 10%, and Richardson 6%? I don’t think so. Even though Clinton’s number has been higher lately, the similarity is interesting, and might imply that once the campaign heats up post-Iowa, there could be as much flexibility in national numbers as there was in 2004. Of course, there are only 106 in the least likely caucus goers sample, so it might be best not to put too much stock in those numbers.
The gap between Edwards support among most likely caucus goers, and least likely caucus goers, is statistically significant. I don’t know if this is good for Edwards, showing that he has hard support, or bad for Edwards, showing that he might be close to a ceiling because he isn’t doing as well among those who are not paying as much attention yet.
As far as the inflated poll theory goes, having been burned so many times about claims that a candidate I like has some sort of huge turnout machine that will prove the polls wrong (see both Dean and Kerry in 2004), that if I were an Edwards supporter I would be extremely wary of using this poll to argue that he is actually ahead. Perhaps Edwards does hold a narrow lead among the most likely caucus goers, but with four months to the caucus (at least), how can we really know what a likely caucus-goer is at this point? That is why I simply cannot take this poll as proof of the Inflated Clinton Poll Theory. It is simply too early to rely on “likely voter” screens.
Now, with all this said, it is still obviously very close in Iowa. The current, four-poll average (all polls taken July 23rd or later) currently stands at Clinton 26.2%, Edwards 24.0%, Obama, 20.1%, Richardson 11.1%. Among all four of those candidates, that average is probably the least good news for Edwards. Even so, he is clearly in the game in Iowa. This is shaping up to be an exciting, four-person campaign.
On the Republican side, Romney is walking away with Iowa, currently holding a dominating, 27%-11% lead over second place Giuliani. If you are the only candidate over 15% in Iowa, the caucus is yours to lose.