Now Roberts explains the failure of the mandate to satisfy the Commerce clause is not the "end of the matter":
Because the Commerce Clause does not support the individual mandate, it is necessary to turn to the Government’s second argument: that the mandate may be upheld as within Congress’s enumerated power to “lay and collect Taxes.”
The Government’s tax power argument asks us to view the statute differently than we did in considering its commerce power theory. In making its Commerce Clause argument, the Government defended the mandate as a regulation requiring individuals to purchase health insurance. The Government does not claim that the taxing power allows Congress to issue such a command. Instead, the Government asks us to read the mandate not as ordering individuals to buy insurance, but rather as imposing a tax on those who do not buy that product.
Under the mandate, if an individual does not maintain health insurance, the only consequence is that he must make an additional payment to the IRS when he pays his taxes.
That, according to the Government,means the mandate can be regarded as establishing a condition—not owning health insurance—that triggers a tax—the required payment to the IRS. Under that theory, the mandate is not a legal command to buy insurance. Rather, it makes going without insurance just another thing the Government taxes, like buying gasoline or earning income.
And if the mandate is in effect just a tax hike on certain taxpayers who do not have health insurance, it may be within Congress’s constitutional power to tax. The Government asks us to interpret the mandate as imposing a tax, if it would otherwise violate the Constitution. Granting the Act the full measure of deference owed to federal statutes, it can be so read...
While the individual mandate clearly aims to induce the purchase of health insurance, it need not be read to declare that failing to do so is unlawful. Neither the Act nor any other law attaches negative legal consequences to not buying health insurance, beyond requiring a payment to the IRS. The Government agrees with that reading, confirming that if someone chooses to pay rather than obtain health insurance, they have fully complied with the law.