Well...THIS is what is going on, the Associated Press has over-weighed it survey toward Democrats. The next two charts come directly from the AP survey document.
That "none of these number may seem a bit high, that's because it is. I assume they mean people who are members of minor parties. In the 2008 presidential election, minor parties earned 1.42% of the vote. Does the AP really believe that Americans will vote minor parties at a rate 12x larger than they did four years ago?
When you add up the Independents and None of these its comes to 31% Democrat/ 22% GOP/ 46% other, or Democrat +9
When pushed the respondents to the AP poll showed their political leanings:
When you include the "leaners," the respondents are 49% Democrat/37% GOP/14% neither or Democrat +12. Compare those party preferences to Gallup or Rasmussen and the bias becomes evident:
Which split is correct? Lets compare them to the results of the past two elections:
The 2008 Election was a wave election for the Democrats, the Mid-Terms were a wave for the GOP. My friend Ed Morrissey (the official research geek of the conservative blogisphere) wrote in a post on Hot Air the giant Democratic wave of 2008 resulted in a D+7 turnout and the 2010 GOP wave resulted in neither party getting a turnout advantage.
One could make a case for the Gallup D+4 as it is in between '08 and '10, and can even make a case for the Rasmussen number if you assume the negative feeling about Obama's performance will motivated more people to switch parties and/or more Republicans to show up at the polls.
However there is absolutely no excuse for the Associated Press splits. Well there is one excuse, trying to skew the result toward Barack Obama.