Chief Justice John Roberts ultimately sided with the Supreme Court's four liberals in upholding the Affordable Care Act, in effect showing the deference that President Obama had said in April was due to "a law that was passed by a strong majority of a democratically elected Congress."
But in writing the majority opinion, Roberts didn't afford the administration a complete victory.
Back in April, Obama had warned that it "would be an unprecedented, extraordinary step" if the Supreme Court overturned the health care reform law.
In the opinion, Roberts wrote:
This case concerns two powers that the Constitution does grant the Federal Government, but which must be read carefully to avoid creating a general federal authority akin to the police power.
Those two powers are the ones that allow Congress to "regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes" and to "lay and collect Taxes, Duties, Imposts and Excises, to pay the Debts and provide for the common Defence and general Welfare of the United States."
Our permissive reading of these powers is explained in part by a general reticence to invalidate the acts of the Nation's elected leaders. "Proper respect for a co-ordinate branch of the government" requires that we strike down an Act of Congress only if "the lack of constitutional authority to pass [the] act in question is clearly demonstrated." United States v. Harris, 106 U. S. 629, 635 (1883) . Members of this Court are vested with the authority to interpret the law; we possess neither the expertise nor the prerogative to make policy judgments. Those decisions are entrusted to our Nation’s elected leaders, who can be thrown out of office if the people disagree with them. It is not our job to protect the people from the consequences of their political choices.
Yet the ruling's deference only went so far:
Our deference in matters of policy cannot, however, become abdication in matters of law. “The powers of the legislature are defined and limited; and that those limits may not be mistaken, or forgotten, the constitution is written.” Marbury v. Madison, 1 Cranch 137, 176 (1803). Our respect for Congress’s policy judgments thus can never extend so far as to disavow restraints on federal power that the Constitution carefully constructed. “The peculiar circumstances of the moment may render a measure more or less wise, but cannot render it more or less constitutional.” Chief Justice John Marshall, A Friend of the Constitution No. V, Alexandria Gazette, July 5, 1819, in John Marshall’s Defense of McCulloch v. Maryland 190–191 (G. Gunther ed. 1969). And there can be no question that it is the responsibility of this Court to enforce the limits on federal power by striking down acts of Congress that transgress those limits. Marbury v. Madison, supra, at 175–176.
The questions before us must be considered against the background of these basic principles.
Roberts rejected the Obama administration's argument that the controversial individual mandate was valid under the Commerce Clause, because in this case the issue was an absence of commerce:
Construing the Commerce Clause to permit Congress to regulate individuals precisely because they are doing nothing would open a new and potentially vast domain to congressional authority. Congress already possesses expansive power to regulate what people do. Upholding the Affordable Care Act under the Commerce Clause would give Congress the same license to regulate what people do not do. The Framers knew the difference between doing something and doing nothing. They gave Congress the power to regulate commerce, not to compel it. Ignoring that distinction would undermine the principle that the Federal Government is a government of limited and enumerated powers.
So the majority instead went to the government's Argument B:
The most straightforward reading of the individual mandate is that it commands individuals to purchase insurance. But, for the reasons explained, the Commerce Clause does not give Congress that power. It is therefore necessary to turn to the Government’s alternative argument: that the mandate may be upheld as within Congress’s power to "lay and collect Taxes." Art. I, §8, cl. 1. In pressing its taxing power argument, the Government asks the Court to view the mandate as imposing a tax on those who do not buy that product. Because "every reasonable construction must be resorted to, in order to save a statute from unconstitutionality," Hooper v. California, 155 U. S. 648, the question is whether it is "fairly possible" to interpret the mandate as imposing such a tax, Crowell v. Benson, 285 U. S. 22. Pp. 31–32.
And decided the mandate qualifies as a tax:
[A]nalysis suggests that the shared responsibility payment may for constitutional purposes be considered a tax. The payment is not so high that there is really no choice but to buy health insurance; the payment is not limited to willful violations, as penalties for unlawful acts often are; and the payment is collected solely by the IRS through the normal means of taxation. Cf. Bailey v. Drexel Furniture Co., 259 U. S. 20–37.
But it's not a total victory for Obamacare because:
Chief Justice Roberts, joined by Justice Breyer and Justice Kagan, concluded in Part IV that the Medicaid expansion violates the Constitution by threatening States with the loss of their existing Medicaid funding if they decline to comply with the expansion. Pp. 45–58.
The four conservative justices who Roberts tends to side with wanted the entire law thrown out.
In their dissent, Justices Antonin Scalia, Anthony Kennedy, Clarence Thomas and Samuel Alito describe the Affordable Care Act as a "massive state-administered federal welfare program," and argue that the decision should have been a no-brainer:
What is absolutely clear, affirmed by the text of the 1789 Constitution, by the Tenth Amendment ratified in 1791, and by innumerable cases of ours in the 220 years since, is that there are structural limits upon federal power—upon what it can prescribe with respect to private conduct, and upon what it can impose upon the sovereign States. Whatever may be the conceptual limits upon the Commerce Clause and upon the power to tax and spend, they cannot be such as will enable the Federal Government to regulate all private conduct and to compel the States to function as administrators of federal programs.
They wanted every bit of the law invalidated:
The Act before us here exceeds federal power both in mandating the purchase of health insurance and in denying nonconsenting States all Medicaid funding. These parts of the Act are central to its design and operation, and all the Act’s other provisions would not have been enacted without them. In our view it must follow that the entire statute is inoperative.