The Supreme Court's 5-4 decision upholding the Obama administration's health care legislation was a victory for the president, his administration and his party. Their most ambitious legislative achievement has not been nullified, and they are not left in obvious disarray.
But it is only a partial victory and in some ways not a victory at all, both in the short run electorally and in the long run in terms of the constitutional order.
Politically Obamacare, as its critics call it, remains highly unpopular. It's possible that the court decision will boost its support, but unlikely.
Most voters want this law repealed. Mitt Romney and the Republicans want to repeal it. Barack Obama and the Democrats want to preserve it. It's not a winning issue for the incumbent.
Constitutionally, many conservatives are unhappy that Chief Justice Roberts and the four justices generally considered liberal voted to uphold the mandate to buy health insurance as a tax, which Congress is clearly empowered to levy.
But the fact remains that a majority of five justices, including Roberts, also declared that Congress' power to regulate commerce does not authorize a mandate to buy a commercial product. This will tend to bar further expansion of the size and scope of the federal government.
Moreover, the Constitution's limits on congressional power have now become, for the first time in seven decades, a political issue. They're likely to remain one for years to come.
This would not have been true had not the constitutional case against the mandate been advanced by Washington lawyer David Rivkin, Georgetown law professor Randy Barnett and many others.
They did not quite prevail in the Supreme Court, but they changed not only the legal but also the political debate in a way almost no one anticipated three years ago.
Unhappy conservatives grumble that Congress can get around the declaration that a mandate is beyond Congress's enumerated powers by labeling it a tax -- or just by relying on five justices declaring it one.
But there's usually a political price to pay for increasing taxes. That's why Barack Obama swore up and down that the mandate was not a tax. It's why Democratic congressional leaders did not call it one.
Roberts' decision undercuts such arguments, now and in the future. Members of Congress supporting such legislation will be held responsible, this year and for years to come, for increasing taxes.