Massachusetts has had essentially this system since 2006; as a result, nearly all residents have health insurance, and the program remains very popular. So we know that Obamacare — or, as some of us call it, ObamaRomneyCare — can work.

Skeptics argued, however, that Massachusetts was special: it had relatively few uninsured residents even before the reform, and it already had community rating. What would happen elsewhere? In particular, what would happen in California, where more than a fifth of the nonelderly population is uninsured, and the individual insurance market is largely unregulated? Would there be “sticker shock” as the price of individual policies soared?

Well, the California bids are in — that is, insurers have submitted the prices at which they are willing to offer coverage on the state’s newly created Obamacare exchange. And the prices, it turns out, are surprisingly low. A handful of healthy people may find themselves paying more for coverage, but it looks as if Obamacare’s first year in California is going to be an overwhelmingly positive experience.

What can still go wrong? Well, Obamacare is a complicated program, basically because simpler options, like Medicare for all, weren’t considered politically feasible. So there will probably be a lot of administrative confusion as the law goes into effect, again especially in states where Republicans have been doing their best to sabotage the process.