When President Obama signed the Affordable Care Act two years ago, the law's proponents (including me) were confident of two things: That it would become more popular with time and that it would make our health care system more humane and efficient.

History has not been kind to the first prediction. Most of the law’s components command broad support: Overwhelming majorities still support the requirement that insurers cover people with pre-existing conditions, for example. But overall the Affordable Care Act is unpopular. And while those who wish to keep or strengthen it outnumber those who wish to repeal it, the intensity clearly lies with the latter.

Those critics will have one last chance to get their way, in the elections this November. The Supreme Court, which next week hears oral arguments in legal challenges to the law, may help them on their way.

On the other hand, the second prediction looks pretty good, at least to this point. Already more than two million young adults have gotten health insurance through their parents’ policies. More than five million seniors and people with disabilities have saved more than $3 billion on prescription drug costs, according to the Department of Health and Human Services. Millions of Americans have consumer protections that, for those unlucky to need them, have made a real difference in their lives.

Of course, it won’t be until 2014 that we see the really big changes in health insurance coverage —the expansion of Medicaid to include everybody with income below 300 percent of the poverty line, the creation of a marketplace with subsidies where individuals and small businesses can get affordable insurance without discrimination. Undoubtedly this helps explain the public’s ambivalence.