Polls have shown this to be true in various ways.
First, a new Washington Post-ABC News poll shows that about three times as many Republicans view Obamacare as one of the most important issues in the 2014 campaign as Democrats who say the same.
The last WaPo-ABC poll showed the same thing in a different way. That poll showed 19 percent of opponents of the Affordable Care Act said it was one of the most important issues, while 11 percent of supporters said the same.
(The older poll measured a larger group -- opponents of Obamacare rather than all Republicans -- which accounts for the lower figure (19 percent) rather than the 26 percent. But the overall, raw anti-Obamacare advantage is about the same in each poll, approximately three-to-one.
A big reason there are so few people rallying around the law is that, even among those who support it, they don't necessarily think it's helping or is going to help.
While support for Obamacare has generally been in the low 40s, only about half of supporters think it will actually be a net-positive over the long haul and make things better
in the U.S. health-care system for their families' health-care situations.
And even fewer -- 14 percent -- say they currently see benefits accruing.
By contrast, a strong majority of those who oppose the law think it will have a negative effect on them over the long haul, and around half see it having negative impacts even as we speak.
(Update: Obamacare supporters point out that 37 percent of people think the law will benefit the country, rather than just themselves -- a valid point. But we would argue that personal impact is much more important when it comes to enthusiasm and electoral impact.)
In other words, opponents of the law are more numerous, more passionate and more dreadful of things to come. Supporters are fewer, less passionate and not terribly convinced that the program they support will even bear fruit.
In politics, voting against something is always a stronger motivating force than voting for something. That's definitely the case when it comes to Obamacare.
And until/unless Democrats get fired up about Obamacare, they're probably in trouble in the 2014 election.