Obamacare is not popular. In the latest tracking poll from the Kaiser Family Foundation, 47 percent of respondents said they have an unfavorable opinion of the law, while just 35 percent said they view it favorably. The numbers haven’t changed that much over time and they’re pretty similar to what other surveys have found. The polls are a little deceiving: People don't want to repeal the Affordable Care Act and, by and large, they like the component pieces. But the overall public reaction has been something less than enthusiastic.

One reason is that the program got off to such a dreadful start. It was exactly a year ago this Wednesday, on October 1, that the Administration launched healthcare.gov—and then watched, helplessly, as it failed. It would take officials nearly two months before they got the site working. The same was true in many states. During this time, insurers were cancelling expiring policies that didn’t comply with the Affordable Care Act’s new standards, forcing somewhere between a few hundred thousand and a few million Americans to search for new coverage. The law’s political opponents seized on the stories of disruption, real and imagined, to argue that the law was a debacle.

Today they make the same argument. In the right-wing press, and among Republican politicians, Obamacare hasn’t simply failed. It’s been a catastrophe. Senator Ted Cruz regularly calls it “the disaster that is Obamacare” Wall Street Journal editorial writer Holman Jenkins, Jr., compares it to the crisis in the Ukraine. The New York Post editorial page just gave the law an "F." Its logic: "About the best thing that can be said about ObamaCare’s first year is that it wasn’t quite as bad as some critics predicted. But it isn’t even close to what we were promised — and nowhere near a passing grade."

The data tell a different story. The Affordable Care Act has real flaws and shortcomings, and pretty much any week you can find a new story about one of them. On Monday, for example, the New York Times had an article about people discovering they owe large medical bills because, during an emergency, they received care from a physician who wasn't part of their insurance network. The next open enrollment period begins in just a few weeks and, already, advocates are bracing for new glitches. But if you focus on the big picture, the available evidence suggests that the Affordable Care Act is working pretty much as its designers envisioned it would.

Critics can legitimately take issue with the law's goals and principles. That's a matter of philosophical preference, after all. Performance is another matter.