Obamacare has been an extremely controversial bill ever since its passage, and as it turns out the fact that it is so polarizing may be the reason why it’s not enjoying much success in many state, even while states like California have just shown new numbers that indicate it is a big hit in the Sunshine State, as we recently reported. But what are the core reasons behind its mixed success?

According to an editorial in the Chicago Sun-Times, it’s Republicans fault. After all, they were able to figure out in California, where more than two-thirds of those who were not insured before the passage of the ACA just three years ago now have health coverage, but in conservative states, Obamacare is landing with a thud.

The Sun-Times argues it’s all about cooperation, and that if truly given a chance to work, Obamacare can get people off the uninsured roles and into good coverage. But conservative states have actively attempted to thwart the ACA by either refusing to work with the law or trying to scuttle it legally or both. Without the states’ cooperation, the Sun-Times writes, Obamacare is not going to be able to work to its full effect.

That’s not to say the ACA hasn’t had its share of problems ever since it was passed. Its website crashed when people tried to signup for coverage when HealthCare.gov first rolled out, and then there were the huge amount of legal challenges from conservatives, which were ultimately shot down by the Supreme Court. And the legal challenges are nowhere near over: Republicans, having taken control of the House and Senate, have set their sights on the law itself, attempting to defeat it in the legislative arena where they couldn’t in the legal arena. And if they can take the White House in 2016, they’ll have even more power to do so.

The Sun-Times claimed in its editorial, however, that the big numbers in California prove that the law can work with states that cooperate, and California is in fact the perfect laboratory for the law: it’s a huge state with a lot of uninsured people, it has a tremendous amount of diversity, and it has state government that has fully cooperated and attempted to make the transition to ACA as smooth as possible for its residents.

The left will certainly hold up this state’s results as proof that Obamacare is a good law. But that might not matter if Republicans get their way now that they control Congress.