Burying the bad news for Obama on immigration

The relative popularity of Obama’s DREAM immigration decree (by 10-15 points in a new Quinnipiac swing state poll) is being called “good news” for the president. But if it’s so popular, then why in the same poll do more voters in all three swing states–Florida, Ohio, and Pennsylvania–say it makes them less likely rather than more likely to vote for Obama? In Ohio and Pennsylvania about twice as many voters say Obama’s new policy makes them less likely to voter for him than say it makes them more likely (27% to 11% in Ohio, 27% to 12% in Pennsylvania).

I’m not sure how to reconcile the two sets of numbers (maybe Mystery Pollster or the aptly named Sean Trende can help). You’d think the contrasting results mean that voters who care about the issue are affected differently than voters who don’t care. That can’t be good news for the president, unless most of 11% who are favorably moved are previously undecided swing voters while the bulk of the 27% who are repelled were all voting against Obama anyway. Are such differentials possible? Maybe–if anti-Obama voters care much more about opposing immigration amnesties than pro-Obama voters care about supporting those policies. A sub issue: How do voters who would never vote for Obama answer the question? Do they say his immigration decision didn’t affect them (since their chance of supporting him was zero anyway)? Or do they say it made them “less likely” on the grounds that it reduced the infinitesimal chance that they’d support him even further, to half an infinitesimal chance? I assume the latter, but does anybody know?