We’re coming up on the anniversary of Barack Obama’s first year in office. How’s he doing so far?

“A good, solid B‑plus” — that’s the grade 44 gave himself when Oprah asked him in December. That must be a relief to anyone out there still worried about this president’s self-esteem.

Is it accurate, though? How should we grade presidents, anyway?

Pundits and historians typically ask questions like: Is he popular? Has he worked his will on Congress? And, does he aspire to be a “transformational” president — dreaming big and daring great things?

Those metrics reek of value-free power worship. We shouldn’t judge presidents based on whether they please the crowd or “transform” the country. What if the country doesn’t need to be transformed?

When Obama gave himself a high B, former George W. Bush consigliere Karl Rove pounced, pointing out that 44 had “the worst [popularity] ratings of any president at the end of his first year.”

But what’s popular isn’t always good, and vice versa. If transient public favor is the true measure of success, then Lady Gaga is the singular artistic genius of our age.

Nor should we grade presidents on whether they manage to ram their agenda through. If that merits high grades, then Bush’s first term was an A‑plus: He got Congress to authorize a disastrous war in Iraq and pass a prescription drug entitlement that’s going to help bankrupt the country. Teacher, give that kid a smiley-face sticker!

Historians usually try to let events cool before they bring out the red pen. But their standards are just as warped as pundits’ — which is why the perennial presidential ranking polls reward nation builders and war leaders, while demoting presidents content to preside over peace and prosperity.

In a recent Washington Post retrospective, historian David Kennedy downgrades Obama for his “Clintonesque” record of legislative success, while scholar Robert Dallek laments the fact that Obama lacks the “advantage” FDR had of using the Great Depression to whip the opposition into line.

Our Constitution spells out a very different benchmark for presidential success: fidelity to the oath of office.

As constitutional scholar Gary Lawson notes, the Constitution prescribes the specific words the president has to affirm before assuming power (as it does for no other office). It requires him to “faithfully execute the Office” and “preserve, protect, and defend the Constitution.”

The implications of that standard are quite radical, in Lawson’s view: “[T]he new President’s first obligation is to veto pretty much every bill sent to him and recommend the repeal of pretty much everything in the United States Code.”

Maybe you’re not willing to go that far. But surely “first do no harm” is a minimum requirement for fidelity to the constitutional oath. A president who takes the oath seriously shouldn’t add new constitutional violations to those committed by his predecessors.

So does Obama’s leading criminal justice initiative, expanded hate crime laws, which flirt with thought crime and ignore the fact that, as Chief Justice John Marshall put it in 1821, “Congress cannot punish felonies generally.”

Meanwhile, the president runs the ongoing bailout as if the Constitution makes him commander in chief of the U.S. economy, while his Justice Department defends the unconstitutional proposition that the federal government can ban union- or corporate-funded ads and movies that mention federal candidates by name.

All in all, a miserable first-year record.

True, other recent presidents have violated the Constitution just as flagrantly. But give Obama time: He’s just getting started.

It’s true too that the standard advanced here — fidelity to the oath — is one that few presidents have lived up to over the last 100 years. But again, so what? It’s a standard that should at least be part of the debate.

Besides, expecting less of our chief executives reflects what Bush, in another context, once called “the soft bigotry of low expectations.” Who says we have to grade presidents on a curve?