Call it the stupidity of hope. A lot of conservatives are twisting themselves into knots in an attempt to portray last week’s Supreme Court decision on Obamacare as a victory. Their reasoning: Chief Justice John Roberts’ opinion rejected the Obama administration’s arguments that the clause in the U.S. Constitution granting Congress authority to regulate interstate commerce gives the government the right to force individuals to buy healthcare.

“Thursday, the Roberts court vindicated all of our arguments about why the individual insurance mandate exceeded the commerce power,” wrote Georgetown law professor Randy Barnett, one of the foremost opponents of the healthcare law, adding: “Constitutional turning points have occurred before in America, and sometimes in cases where the apparently losing side went on to be history’s winner. It can happen again. Today is only the beginning.”

Radio talk-show host and columnist Michael Medved said the court’s decision was cause for party time: “All right-wingers with integrity should feel encouraged by the fact that judicial restraint is alive and well.” Even the estimable George Will said conservatives should declare they won the healthcare war and go home. “Conservatives won a substantial victory Thursday,” he wrote. “The physics of American politics — actions provoking reactions — continues to move the crucial debate, about the nature of the American regime, toward conservatism. Chief Justice John G. Roberts Jr. has served this cause.”

As one of Ernest Hemingway’s disillusioned, world-weary characters said at the end of The Sun Also Rises, “Isn’t it pretty to think so?” Because Roberts, after devoting a couple of pages of his opinion to scourging the administration’s argument about the commerce clause, turned around and said it didn’t matter: The government, through its power to tax, can regulate most anything it wants.

In a bit of lawyerly tap-dancing to rival Bill Clinton’s infamous argument about “what the meaning of the word ‘is’ is,” Roberts declared that the law’s fines to be levied against anybody without health insurance weren’t “penalties” but “taxes.” And that, Roberts continued, “makes going without insurance just another thing the government taxes, like buying gasoline or earning income.”

No matter that back in 2009, Obama vigorously denied that the penalties were taxes: “For us to say that you’ve got to take a responsibility to get health insurance is absolutely not a tax increase . . . I absolutely reject that notion.” Or that Roberts himself, elsewhere in his opinion, said Congress clearly didn’t intend the penalties as taxes. Case closed! One-sixth of the U.S. economy seized by the state! Some conservative victory. As King Pyrrhus of Epirus declared after observing a corpse-littered field where his army fought the Romans, “Another such victory and I am undone.”

And undone we shall be, soon enough. Every single reductio ad absurdum argument put forth against the healthcare law during its long judicial slot to the Supreme Court is no longer absurd at all. The government cannot order you to eat broccoli or buy a GM car. But it can tax the daylights out of you if you don’t, and put you in jail if you don’t pay the taxes. If you think that nanny-state forces won’t, soon enough, attempt to enact a tax for not exercising, or not owning an electric car, or not partaking of some other progressive fad of the moment, your imagination is sadly lacking.

Speculation is now rampant that Roberts originally sided with the other four conservative justices who opposed the law, but changed his vote out of fear that a vote on ideological lines would discredit the court. (Funny how the advocates of the nonpartisanship argument never suggest that any of the liberals abandon their voting bloc.) If so, it sure didn’t work. Roberts’ opinion so appalled the other four conservative justices that they bound themselves together in an unprecedented single unsigned dissent.

Meanwhile, a Rasmussen poll taken after the ruling showed an 11-point jump in the percentage of Americans with a negative view of the court, and a five-point jump in the number who believe the justices pursue their personal political agendas rather than remaining impartial. Don’t view that as a penalty for legal sophism, Justice Roberts. Just think of it as a prestige tax.