But if you look here, you'll see that Justice Roberts made somewhat the same argument that I made about the health insurance mandate, namely that a law that's constitutional when written in one language needs be constitutional when written in a different language.
This invariance to translation is, from my reading of Justice Robert's decision, a legal principle. So it's remarkable that four justices didn't acknowledge this principle.
Robert's opinion, posted here, draws the equivalence between a tax and a penalty. Basically, he ignored the mandate and asked the question whether Congress has the power to tax people who don't buy good X. He concluded it does.
How does this square with taxation of, say, labor earnings? Well, if we call good X, leisure, it's clear that Congress has the power to tax people who don't buy leisure (which happens when people don't work, with the price being the lost wages), i.e., who earn money.
My blog focused on a different equivalence, which Roberts seems to reject. I said that it's mandating someone to buy X and then subsidize their purchase based on their income is equivalent to giving the person X and taxing him/her on a progressive basis.
Robert, though, would, I presume, say, "No. You are ignoring the fact that in the case at hand, the purchase of X is not absolutely mandated (no one is force fed brocoli) because people can refuse to purchase X and pay a penalty."
But I'd reply, "No. When I said Congress would give people X, I should also have said that it would also give people the right to refuse to take X, in which case the tax would be adjusted to equal the penalty in the case where we used the ACA's language."
Congress clearly has the power to give people X and let them refuse its receipt. Some people, for example, refuse, on principle, to take their Social Security benefits and do so by waiving them with the Social Security office if they had previously taken them and wanted to stop the checks or by simply not applying for them. And Congress clearly has the power to tax to pay for X (e.g., to pay for Social Security benefits). Finally, Congress can tax people at different levels/rates is they receive X or not. Indeed, those who waive or don't apply for their Social Security benefits pay different federal income taxes than those who do since the receipt of Social Security benefits is included, if it exceeds certain thresholds, taxable income.
It seems, then, that Roberts used the principle of translation invariance to accept the penalty for not buying X, but he didn't apply it to the case of those who accede to the "mandate." Instead, he said the mandate per se (as opposed to the penalty for not complying with the mandate) was unconstitutional and was not governed by the Commerce Clause. In so saying, the Court has changed the interpretation of the Commerce Clause potentially for all time.
The other disturbing feature of Robert's decision is he made no acknowledgement that the Commerce Clause's limiting principle, at least in practice, is situations of market failure. Health insurance is the poster child for market failure.
My bottom line -- Roberts should have either judged the mandate aspect of the ACA as lawful based on the translation invariance principle or lawful based on the proposition that Congress, under the Commerce Clause, has the right to regulate Commerce when markets fail.
HuffPost Politics brings you the top political stories three days a week. Learn more