Obamacare -- the signature legislation of President Obama's White House -- is constitutional.

Of course, Thursday's U.S. Supreme Court ruling is more complicated, and some aspects of his health care reform have been reigned in. But, for the most part, the Supreme Court's decision is favourable to the White House. Very favourable.

Thursday's decision is significant for the administration in what it didn't do, as opposed to what it did. The Supreme Court didn't strike down the law; it didn't embarrass the White House; it didn't undo years of work by Democrats.

It was a close call. For nearly four years, Republicans have worked overtime trying to find a way to discredit President Obama's health care reform efforts. They refused to co-operate with Democrats in the drafting of the legislation; they have held countless townhalls and meetings with dramatic (and overheated) rhetoric; they have used their Congressional power to hold hearing after hearing to question the administration and flush out awkward details.

For weeks now, court watchers speculated that the White House had ended up doing a better and faster job of destroying Obamacare than its Republican opponents ever dreamed possible. It was the administration, after all, that had expedited the case against its own legislation and then forwarded an awkward argument in front of the Justices.

So likely did it seem that key portions of the legislation would be struck down, that CNN initially reported incorrectly that it was ruled unconstitutional. "The Justices have just gutted, Wolf, the centerpiece provision of the health care law," CNN reporter John King declared. He added that it was "a direct blow to President Obama."

Thursday, though, there was no direct blow. The requirement that people be forced to buy health insurance -- the so-called mandate -- stood the court challenge (albeit not as a requirement, but as a tax).

This isn't simply a political win for the White House, establishing that the law is constitutional. It literally saves the legislation.

Without the mandate, the law couldn't possibly work.

Democrats have spent years mulling over how to expand coverage to the millions of uninsured Americans. Many favour the sort of government-run system found in countries like Canada and Britain.

Burned by public revolt against President Clinton's efforts to expand coverage in the 1990s, Democrats championed something of a compromise. "No" to government-run health, but "yes" to a more regulated system of private insurance. Forget Canada, Democratic policy makers decided, but push the American system closer to Switzerland's or Belgium's.

To make a complex web of regulations work, such a system requires nearly everyone to participate. That way, a 20-year-old man who has never seen a doctor will help pay for the costs of the 60 year-old woman with a cardiac history.

Canadians don't often think about the economics of private health insurance, so let me give a non-insurance analogy. Say you own an all-you-can-eat buffet. To make up for the people who pile their plates sky-high with food, your restaurant needs customers who eat sparingly. Obamacare forces everyone to the health-insurance buffet -- the people who need care, but also, the healthy ones who don't feast on meals of health care, so to speak.

Had the Supreme Court struck down the mandate, Obamacare would have had all the regulations and costs, but lacked the young, healthy people to make it work. You can understand why the White House was quiet with anxiety all week. This was a close call.

But with the court challenge behind them, all is not well for the White House. Yes, the Supreme Court did no serious damage to the signature legislation. But the implementation of Obamacare seems anything but straight forward. Costs have soared despite the fact that most reforms don't kick in until 2014; several states have effectively rebelled; one basic reform (the long-term care insurance) was already scrapped.

After nearly four years of hard work by President Obama, in other words, the debate over American health care seems no closer to resolution.

Canadians have a tendency to look at American health care with a jaundiced eye. We see heavy costs and uneven quality. I suspect most Canadians have been sympathetic with the President's goals of universal coverage -- something we take for granted north of the 49th parallel. All this talk of court challenges, mandates, and constitutionality seems a bit exotic.

But the debate in the United States isn't so foreign. Like practically ever other Western nation, the U.S. is attempting to deal with the high-tech, high-expense medical revolution that has transformed health care. In Washington today, post Supreme Court ruling, they are thinking long and hard about health-care reform. But today, post Supreme Court ruling, government officials in Winnipeg (and Regina, and Toronto, and every other provincial capital) are thinking long and hard about health-care reform, too.

With the Supreme Court ruling, the debate continues in America. And everywhere else across the Western world.