Max Baucus thinks it might be a “train wreck.” David Brooks is predicting chaos. And Democratic senators are telling the White House they are panicked. They’re all talking about Obamacare and what happens next year, when it starts making insurance coverage available to nearly all Americans.

Believe it or not, the conversation represents progress. Instead of talking about whether we should have a health care reform law, we’re talking about how well (or not well) the law is going to work. So let me spoil the surprise for you: It’s not going to work as well as many of us would like, and the initial adjustment may not be easy. The whole enterprise is going to be a work in progress. And that'll be ok—because it will still do a lot of good and make life better for most people, particularly with the passage of time.

As even Obamacare’s most ardent defenders have said from the start, the law is far from ideal. The architects of reform had to make all sorts of compromises, just to get the law past lobbyists and obstructionist Republicans. And then, after finally enacting the historic legislation in early 2010, they had to spend most of the next three years fighting repeal. In Washington, Republican congressional leadership has repeatedly blocked funding for implementing the law. At the state level, conservative officials are at best indifferent to its success and at worse outright hostile to it. This last part is no small thing, given the leeway state officials have over the law's implementation. In states like Florida and Texas, officials have already indicated they won't be expanding eligibility for their Medicaid programs—depriving millions of health insurance.

This helps explain why even supporters of the law are nervous about what happens this fall, when the new insurance “exchanges” are supposed to open for business. The exchanges are the new online marketplaces through which people without employer insurance can buy insurance directly and, depending on their incomes, qualify for tax credits that offset the cost. The idea is to make them pretty simple: You go online, enter in some financial information about you and your family, and learn what kind of insurance you can get. If you’re poor, you’ll be instructed to enroll in Medicaid, assuming your state makes it available. If you’re not poor, then you’ll get to choose from among a set of regulated plans—each with a comprehensive set of benefits, and priced in ways that you can make real apples-to-apples comparisons. And if your income is less than four times the poverty line, or about $94,000 a year for a family of four, you’ll learn about tax credits to offset the cost of the premiums—the less money you make, the bigger the tax credits you get will be.

But constructing such a system is complicated. It requires, among other things, collecting a lot of information. A prototype form that the federal government released in March ago had 21 pages, although it would seem like less online and not everybody would have to fill out the whole thing. A well-functioning exchange also requires seamless, near-instant communication between the federal government (which is in charge of the tax credits) and the states (which run Medicaid and, in at least some states, will be running the exchanges). That’s a substantial information technology challenge, particularly since the security needs to be ironclad. Even the states most committed to the new law, and with the best resources for doing so, have struggled with this. In conversations over the last year, I’ve heard the phrase “white knuckles” more than once. You can imagine what it’s like in states where officials are ambivalent.