Like many major polls these days, these guys seem to have their sampling all wrong. Taking into the above oversampling, the results should be more like:
Virginia: Romney + 4%
Wisconsin: Obama + 3.5%
Colorado: Romney + 3%
Here’s how I based this: If we look at Gallup’s state party numbers, which likely takes into account independents leaning either Democrat or Republican, we see the following party identifications (approximates):
Virginia: Republican plus 1%
Wisconsin: Democrat plus 4.5%
Colorado: Republican plus 3%
However, this poll samples the following:
Virginia: Democrat +7
Wisconsin: Democrats +7
Colorado: Republicans plus 5
The difference between the poll and Gallup’s party identification numbers is:
Virginia: oversampled Democrats by 8%
Wisconsin: oversampled Democrats by 2.5%
Colorado: oversampled Republicans by 2%
Apply those oversampling numbers to the polls results and you get this:
Virginia: Romney + 4%
Wisconsin: Obama + 3.5%
Colorado: Romney + 3%
By the way, here’s where you can find Gallup’s state party id numbers:
http://www.gallup.com/poll/125066/State-States.aspx