Or, “why did Chief Justice John Roberts vote to uphold Obamacare’s individual mandate?” Also …
“Why Democrats didn’t just explain to the American people what Obamacare’s individual mandate was in the first place.”
UPDATE: Here are some of the relevant points from the SCOTUS decision (and in reading them, you can see why so many media outlets got it initially wrong…
1. They ruled that Congress CANNOT compel you to buy insurance, because it cannot regulate “inactivity” (just as conservatives have said):
The Framers knew the difference between doing something anddoing nothing. They gave Congress the power to regulate commerce, not to compel it. Ignoring that distinction would undermine the prin-ciple that the Federal Government is a government of limited andenumerated powers. The individual mandate thus cannot be sus-tained under Congress’s power to “regulate Commerce.” George Will takes solace in that, as well everyone should. That aspect of the mandate — the part that presumed government could force you to buy a private industry’s product, was always the part that bothered me, and I’m no conservative (I later got over it.) But of course, Democrats never proposed that. They proposed a tax on those who don’t buy it, only they didn’t want to admit it at the time…
2. The individual mandate cannot be utilized to expand federal power:
(b) Nor can the individual mandate be sustained under the Nec-essary and Proper Clause as an integral part of the Affordable Care Act’s other reforms. Each of this Court’s prior cases upholding lawsunder that Clause involved exercises of authority derivative of, andin service to, a granted power. E.g., United States v. Comstock, 560U. S. ___. The individual mandate, by contrast, vests Congress withthe extraordinary ability to create the necessary predicate to the ex-ercise of an enumerated power and draw within its regulatory scopethose who would otherwise be outside of it. Even if the individualmandate is “necessary” to the Affordable Care Act’s other reforms,such an expansion of federal power is not a “proper” means for making those reforms effective.
2. The mandate must be described as a tax:
The most straightforward reading of the individual mandate is thatit commands individuals to purchase insurance. But, for the reasonsexplained, the Commerce Clause does not give Congress that powe r.It is therefore necessary to turn to the Government’s alternative argument: that the mandate may be upheld as within Congress’s powerto “lay and collect Taxes.” Art. I, §8, cl. 1. In pressing its taxingpower argument, the Government asks the Court to view the mandate as imposing a tax on those who do not buy that product. Be-cause “every reasonable construction must be resorted to, in order tosave a statute from unconstitutionality,” Hooper v. California, 155U. S. 648, 657, the question is whether it is “fairly possible” to interpret the mandate as imposing such a tax,
Crowell v. Benson , 285U. S. 22, 62. Pp. 31–32.
… (a) The Affordable Care Act describes the “[s]hared responsibilitypayment” as a “penalty,” not a “tax.” That label is fatal to the appli-cation of the Anti-Injunction Act. It does not, however, control whether an exaction is within Congress’s power to tax. In answering that constitutional question, this Court follows a functional approach, “[d]isregarding the designation of the exaction, and viewing its sub-stance and application.” United States v. Constantine, 296 U. S. 287,294. Pp. 33–35.
(b) Such an analysis 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 bythe IRS through the normal means of taxation. Cf. Bailey v. DrexelFurniture Co., 259 U. S. 20, 36–37. None of this is to say that pay-ment is not intended to induce the purchase of health insurance. Butthe mandate need not be read to declare that failing to do so is un-lawful. Neither the Affordable Care Act nor any other law attachesnegative legal consequences to not buying health insurance, beyond requiring a payment to the IRS. And Congress’s choice of language— stating that individuals “shall” obtain insurance or pay a “penalty ”— does not require reading §5000A as punishing unlawful conduct. It may also be read as imposing a tax on those who go without insur-ance. See New York v. United States , 505 U. S. 144, 169–174.Pp. 35–40.
Good explanation of the ruling and video of President Obama’s response to it here.