First, Democrats believed that Obamacare would become popular after the initial furor surrounding the law's passage died down. It didn't die down, and Democrats probably lost the House in the 2010 midterm election as a result. Then the law's supporters argued that once the law's early benefits—for young adults, seniors, and preventive care—kicked in, public opinion would take a turn. The benefits went into effect, but public opinion stayed the same.
Finally, the law's backers argued that once the law's biggest benefit, its coverage expansion, took effect, the law would start down the road to popularity. The coverage expansion kicked in, and for almost six months now, people have been using the coverage they have under the law. It's still unpopular.
An AP-GfK poll released today finds that, while premium sticker shock is not proving a big problem for those who got coverage under the law, many more people still oppose the law than favor it. From the AP's news report:
A new Associated Press-GfK poll finds that public opinion continues to run deeply negative on the Affordable Care Act, Obama's signature effort to cover the uninsured. Forty-three percent oppose the law, compared with just 28 percent in support.
The poll suggests both lower support and lower opposition than other surveys, but in terms of the gap between support and opposition, it's not an outlier. Here's RCP's poll average for public approval of the health care law over the last year:
As you can see, there was a spike in opposition when the exchanges crashed on open last fall. That effect seems to have mostly worn off, but broadly speaking, opposition remains high and favorability remains low.
Meanwhile, the law's supporters are basically out of excuses to explain why it's not popular now but it will be in the near future. The public has been pretty clear from the beginning that, overall, they don't like Obamacare. Now they've spent six months living with its coverage expansion, and they still don't. It's of course always possible that opposition will moderate at some point, but in the near term at least it doesn't seem particularly likely that it will. The law's benefits have kicked in, people are experiencing the effects, and there's no obvious potential turning point left.