What makes America exceptional? It could be the mythology of perfection: the shining "city upon a hill" imagined by colonist John Winthrop and repackaged by Ronald Reagan to glorify the exercise of U.S. power and influence in the world. Or "American exceptionalism" might mean something different in the 21st century.

Something honest and tangible and, like our times, uniquely aspirational. Something like what Greg Jaffe of The Washington Post described in his provocative essay, "Obama's American Exceptionalism."

Obama's conception is more inwardly focused. It's a patriotism that embraces the darker moments in American history and celebrates the ability of the unsung and the outsiders to challenge the country's elite and force change.

It's a view that one senior White House official said is better suited to a country whose population is growing browner and more accepting of gays and lesbians.

That is a scary thought for some people. I get it: Life is changing so quickly and the future is so uncertain that the past is a pacifier—and so politicians cling to the founding myths of the nation. And yet, Ted Cruz, Jeb Bush, and other GOP presidential candidates critical of Obama's formulation are making a mistake with their retro pitch to a populace that has always looked to the future.

The term "American exceptionalism," first used with respect to the United States by Alexis de Tocqueville, refers to the notion that this country differs qualitatively from other developed nations because of its national credo, ethnic diversity, and revolution-sprung history. It is often expressed as superiority: The United States is the biggest, most powerful, smartest, richest, most-deserving country on Earth.

As I wrote at the start of Obama's second term, American exceptionalism is a recurring character in the nation's narrative. We, the people. Manifest Destiny. Conceived in liberty. Fear itself. Ask not. Morning in America. United we stand. Yes, we can. In times of great change and tumult, presidents seek to inspire beleaguered Americans by reminding them of their national identity.

In perhaps the greatest speech of his presidency, Obama stood at the base of the Edmund Pettus Bridge and used the civil rights movement to tell a different story about America. He spoke of a nation with blemishes and grit that learns from its mistakes and gets better. Greater.

"What could be more American than what happened in this place?" Obama asked. "What could more profoundly vindicate the idea of America than plain and humble people—the unsung, the downtrodden, the dreamers not of high station, not born to wealth or privilege, not of one religious tradition but many, coming together to shape their country's course?"

The normally staid president's voice caught with emotion as he spoke of Jackie Robinson "enduring scorn and spiked cleats and pitches coming straight to his head and stealing home in the World Series anyway." Obama had added the references to "spiked cleats" and pitches thrown at Robinson's head on the plane to Alabama that morning.

"That's what America is," Obama continued, now rising up on the balls of his feet and pointing to the crowd for emphasis. "Not stock photos or airbrushed history or feeble attempts to define some of us as more American than others.

"We respect the past, but we don't pine for the past," he said to cheers. "We don't fear the future; we grab for it. America is not some fragile thing."

Before the address, former New York Mayor Rudy Giuliani had accused Obama of not loving his country. The president responded, essentially: I love my country enough to criticize it. To help make it better. To help it adapt to the times so that it will never perish.

While more subtle than Giuliani, the large cast of GOP presidential candidates use American exceptionalism to measure their patriotism against Obama's. Cruz said in his announcement speech that he's worried that Reagan's vision is "slipping away from our hands." In a foreign policy address, Bush reviewed America's central role in expanding freedom across the globe since World War II. "Only our exceptional country can make that claim," he said. "I have doubts whether this administration believes that American power is such a force."

That is a fair critique of Obama's foreign policy. But by linking the attack to American exceptionalism, Bush reveals how much the GOP has diminished the concept since Reagan: It's a cudgel, not a cure, and it speaks to America's standing abroad rather than America's possibilities to its own people.

Obama's concept of American exceptionalism is not, as critics say, something smaller. It's Reagan-plus: a striving city under constant construction.

Don't believe me? Watch the Selma speech one time with an open mind. See it for what it was: a revolutionary twist on America's tale that is just as inspirational as the story told by Winthrop and Reagan because, like their city upon a hill, Obama's vision of America is as great as we can make it.

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