“The problem of the twentieth century is the problem of the color line,” W.E.B. Du Bois wrote in 1903 — and I will not quibble. But the problem of the 21st century is the problem of culture, not just the infamous “culture of poverty” but what I would call the culture of smugness. The emblem of this culture is the term “American exceptionalism.” It has been adopted by the right to mean that America, alone among the nations, is beloved of God. Maybe so, but on some days it’s hard to tell.

The term “American exceptionalism” has been invoked by Mitt Romney, Mike Pence, Newt Gingrich, Rick Santorum, Mike Huckabee and, of course, Sarah Palin. I would throw in Michele Bachmann, since if she has not said it yet, she soon will because she says almost anything. She is no exception to the cult of American exceptionalism.

The phrase has an odd history. As Princeton history professor Sean Wilentz reminds me, American exceptionalism once applied to the hostility that the American worker — virtually alone in the industrialized world — had toward socialism. Now, though, it is infused with religious meaning, which makes it impervious to analysis. Once you say God likes something, who can quibble?

What God prefers should not be monkeyed with. But certain kinds of exceptionalism raise certain kinds of question. For an industrialized nation, the United States has a very high murder rate and, no surprise, a very high execution rate. We have a health-care system cleverly designed to bankrupt the average person and a political system so dysfunctional that we may go into national bankruptcy, blaming one another for spending too much or taxing too little, but not both. God indeed works in mysterious ways.

American exceptionalism has produced a dysfunctional education system — more than 14,000 school districts, lots of bad (but job-protected) teachers, oblivious parents and students who are too dumb to know they’re dumb. American eighth-graders score 66 points below their Japanese counterparts in math, yet almost 40 percent of American children think they’re good in math. That figure for Japan is 4 percent.

What a Brookings Institution report termed “the happiness factor” occurs pretty much across the board. Brookings should have called the phenomenon the “ignorance-is-bliss” factor, which now may be the true meaning of American exceptionalism. Its current iteration comes in the form of self-esteem, which holds, as best as I can figure, that how you feel is more important than how you perform. A consequence of this is that students in Singapore or Shanghai have almost no self-esteem. But they do, however, know their math.

Let no person think there is not a certain kind of American exceptionalism that I believe in and cherish. It is our astounding capacity for tolerance. European history is a sad, sanguinary tale — massacres, pogroms, population transfers and genocides. Most European nations have rid themselves of pesky minorities. The Germans of Hungary are gone. So, too, the Poles of Germany and, of course, the Jews of almost everywhere. The United States has not been perfect in this regard. The American Indians were virtually extirpated and African Americans suffered plenty. Yet the melting pot — aided by lots of land — turned out to be more true than false. We live among each other, often blissfully ignorant of religion or ethnicity.

It turns out, however, that some of those most inclined to exalt American exceptionalism are simply using the imaginary past to defend their cultural tics — conventional marriage or school prayer or, for some odd reason, a furious antipathy to the notion that mankind has contributed (just a bit) to global warming. Their enemy is what Gingrich calls “the secular left” — people who not only approve of gay marriage but also apparently don’t fly charter as he does.

The huge role of religion in American politics is nothing new but always a matter for concern nonetheless. In the years preceding the Civil War, both sides of the slavery issue claimed the endorsement of God. The 1856 Republican convention concluded with a song that ended like this: “We’ve truth on our side/ We’ve God for our guide.” Within five years, Americans were slaughtering one another on the battlefield.

Therein lies the danger of American exceptionalism. It discourages compromise, for what God has made exceptional, man must not alter. And yet clearly America must change fundamentally or continue to decline. It could begin by junking a phrase that reeks of arrogance and discourages compromise. American exceptionalism ought to be called American narcissism. We look perfect only to ourselves.

cohenr@washpost.com