Editorial writer and columnist

We have two days until the Supreme Court rules on health care — two days until we find out whether Akhil Amar’s life has been a fraud.

Amar is the Yale constitutional law professor (my former teacher), who recently told The Post’s Ezra Klein that a 5 to 4 ruling striking down Obamacare would destroy his faith in the court.

“If they decide this by 5-4,” Amar said, “then yes, it’s disheartening to me, because my life was a fraud. Here I was, in my silly little office, thinking law mattered, and it really didn’t. What mattered was politics, money, party and party loyalty.”

Amar’s cri de coeur was a dramatic but otherwise typical expression of sentiment in legal academia, where it is widely assumed that no serious person could doubt the law’s constitutionality.

Professors have stuck to that view even after a couple of lower federal courts struck down the 2010 law wholly or in part, and after oral arguments in April showed that the five most conservative Supreme Court justices might be leaning against the law, too. Hence Amar’s angst.

Knowing Amar’s eclectic brand of liberalism, I wouldn’t charge him with reading his ideology into the Constitution, though I can’t say the same for all law professors, who tend to be much more liberal than the general public.

Remarkably few of them have shown the perspicacity of Amar’s Yale colleague Stephen Carter, who has written: “Both sides have a point. The mandate to purchase health insurance does indeed run counter to the libertarian strain of the American tradition, and the arguments in support of federal power don’t have a logical stopping place. On the other hand, one must also recall the egalitarian aspects of the American tradition.”

But assume the professors are arguing in good faith, and correctly interpreting precedent: that until now Congress could enact almost any law in the name of regulating interstate commerce, up to and including a limit on subsistence wheat farming.

What, then, led the academics to misread this case?

In a sense, they resemble the conservative leaders of the bar at the dawn of the New Deal. President Franklin Roosevelt’s alphabet soup of federal programs ran counter to established doctrine denying the constitutionality of economic and social legislation, state or federal. Steeped in that tradition, many legal experts recoiled in horror at FDR’s plans.

Amid a Great Depression, and under tremendous pressure from a popular president and his huge congressional majority, however, this expert consensus gave way. The Supreme Court abandoned its laissez faire understanding of the Constitution’s Commerce Clause (among other provisions) so as to permit New Deal programs.

I don’t think this history proves that “politics, money, party and party loyalty” crassly determined the decisions of the 1930s. If that were true, why accord them precedential weight today?

Rather, what it shows is that the United States periodically redefines the role of the federal government in society, in a process that is both political and legal — and, sometimes, more revolutionary than evolutionary. In that sense, we do have a “living Constitution.”

In the 1930s, expanding federal power was innovative, promising. By blessing it, the court aligned itself with the wave of the future, in this country and globally. Ditto for the 1960s. Much of the legislation that resulted — from Social Security to the Voting Rights Act — was indeed progressive.

Today, however, there is nothing new about federal intervention — and much evidence from the past 70 years that big programs produce inefficiencies and unintended consequences.

The post-New Deal consensus about the scope of federal power has broken down amid national, and global, concern over the welfare state’s cost and intrusiveness — a sea change of which the tea party is but one manifestation. Obamacare itself, which has consistently polled badly, fueled that movement.

Much has been made of the fact that Republicans had no objection, constitutional or otherwise, when the individual mandate first surfaced. But that was two decades ago. In today’s changed intellectual, fiscal and political environment, seemingly lapidary constitutional phrases such as “commerce . . . among the several states” can acquire fresh meaning, as they did for the New Deal and at other points in the past.

The brilliance of Obamacare’s opponents lies in spotting that historical opportunity and making the most of it. The legal professoriate, by contrast, reminds me of how William F. Buckley described his arch-conservative magazine in the 1950s: “It stands athwart history, yelling Stop.”