THIS is not the column about the Obamacare rollout I expected to write

If you had told me, months ago, that weeks after the health care law’s coverage expansion went into effect I would be writing about the problems its launch had exposed, I would have assumed I’d be writing about rate shock, rising premiums and the disappearance of many cheap insurance plans — basically, all the problems conservatives have worried will make Obamacare a ruinously expensive failure if they play out as we fear they might.

I may be writing about those issues soon enough. But for now there is a more pressing subject: The online federal health care exchange, the heart of the Obamacare project, is such a rolling catastrophe that it may end up creating a major policy fiasco immediately rather than eventually.
This fiasco has always been a possibility, for reasons inherent in the architecture of the law. When The New Republic’s Jonathan Cohn, the most rigorous defender of the entire reform project, wrote up his “five Obamacare anxieties” in May, the first one was structural: The system’s sustainability depends on getting enough healthy people to sign up, he pointed out, and if they don’t then insurers “will have to raise everyone’s premiums,” which “could create what actuaries call a ‘death spiral’: Rising premiums prompt people to drop out, causing premiums to increase even more.”
Cohn thought such a death spiral was unlikely, and frankly so did I. Between the stick of the mandate, the carrot of subsidies and the planned P.R. blitz, it seemed as if enough Americans would sign up to at least postpone the cost problem and get the system off the ground.