The #1 trouble with polls is that the questions can be easily manipulated to shift the results quite a bit by small changes in wording.
But another problem in interpretation is that "opposition" to certain public policy goals is not well parsed. Kevin Drum gives an example where "opposition" to Obamacare includes a lot of people who don't like it because they wanted it to be even more radical, believing the government should have gone even further or stopped short of the full policy prescription required. But these numbers are typically just lumped in as "opposed" and the conclusion is frequently that all opposed thought the law went too far or should not have been passed.
My gut feel is that this is a non-partisan issue. Just as easily folks could be opposed to, say, tax cuts or the government shutdown because they did not think it went far enough.
As far as Obamacare goes, it will be interesting to see what those numbers look like in 2 months.