Megan McArdle observes that Massachusetts’s health care system, on which Obamacare was based, isn’t working. With insurance companies forbidden to consider pre-existing conditions, people have no reason to buy health insurance until they’re sick, unless the government forces them to do so. Hence the individual mandate, but the individual mandate isn’t working.
POSTSCRIPT: As I noted earlier, the individual mandate wouldn’t solve the problem, even if it did work, unless uniformly low-quality health care is a satisfactory solution.