The technical troubles with Obamacare's exchanges are bad enough that even supporters are turning critical. The Washington Post's Ezra Klein, a longtime champion of the health law, has declared the launch so far a "failure" and a "disaster." Former White House press secretary Robert Gibbs is asking whether anyone will be fired over the botched rollout.

But here's the thing: The serious problems that have gotten the most attention so far may only be the beginning of the headaches for the exchanges.

Right now, the most visible problems are concentrated on the user end, in the registration and enrollment process. Lots of people still can't create accounts in the federal exchange system at all. Others get error messages or hang-ups within the application process. It seems pretty clear that, roughly two weeks after launch, most potential users are effectively locked out of the federal exchange system—and most of those who aren't actually locked out aren't able to complete the transaction process.

But as I wrote last week, there also appear to be serious back end problems as well. On Friday, insurance consultant Robert Laszewski noted that the enrollment system is sending lots of junk information through to insurers.

Here is one example from a carrier–and I have received numerous reports from many other carriers with exactly the same problem. One carrier exec told me that yesterday they got 7 transactions for 1 person—4 enrollments and 3 cancelations. For some reason the system is enrolling, unenrolling, enrolling again, and so forth the same person. This has been going on for a few days for many of the enrollments being sent to the health plans. It has got on to the point that the health plans worry some of these very few enrollments really don't exist. The reconciliation system, that reconciles enrollment between the feds and the health plans, is not working and hasn't even been tested yet.

A separate Washington Post article seems to confirm Laszewski's diagnosis. The Post says that Cigna, which is selling health insurance through the federal exchange system in four states, has "seen 'multiple enrollments' from the same customer on the same day." Another Blue Cross Blue Shield plan told the Post it had also seen the error. The enrollment data error is further complicated by the fact that the applications lack a crucial detail: a time stamp.

And then there's the subsidy calculator that is at the core of the exchange system. The exchanges are not only supposed to allow individuals to compare the sticker prices for insurance available in their area, they are also supposed to allow people to see, in real time, if they qualify for a subsidy—and how much that subsidy is worth.

But even before the exchanges opened for enrollment there were reports that the subsidy calculator was not working correctly. That still seems to be the case. Cigna is so uncertain about the subsidy calculator in the federal exchange that it has issued an official warning to brokers not to attempt to enroll anyone who might qualify for subsidies until November, according to the Post. Cigna isn't alone in its worries either. Jonathan Gruber, an influential Massachusetts Institute of Technology health policy wonk who helped design Romneycare and consulted on the federal health care overhaul, tells Politico that he expects that problems with the subsidy calculator could well last into next year. That's a long time for key functionality to remain broken.

So two weeks in, here's where we're at: Many and perhaps most users can't even get into the federal exchange system. Those who can are often stymied by errors, and can't trust that any subsidized insurance prices they see will be accurate. And then, even if they do manage to get all the way through the system, their applications may not transmit properly to the insurers from whom they are trying to purchase insurance. In short, nothing works. It's a failure at every level.

The administration says it's working on fixes. But the clock is ticking.

Obama administration officials are downplaying problems, and framing current troubles as a rocky start that won't necessarily doom a six-month enrollment project. Open enrollment, they note, doesn't actually end until March 31 of 2014.

But in order for Obamacare to have any chance of success, the exchanges will need to be functional long before then. In order for coverage to start on January 1, individuals will have to complete applications by December 15. And in order to avoid the law's penalty for remaining uninsured, they'll have to be enrolled by February 15 of next year—not the end of March.

In other words, the administration doesn't really have six months to fix problems with the exchanges. Political pressure will build well before the end of March. If there isn't significant progress in a fairly short period of time, I suspect we'll start to see a lot more supporters begin to question the law, or at least start to wonder aloud about what to do with a health care overhaul that simply doesn't work.