Barack Obama has been thought by some of his right-leaning critics to be a bit of a Mau Mau, a zealous anticolonialist, more Kenyan than American, a special pleader for his father’s race. These critics fail to understand, among many things, how Barack Obama Sr.’s experience in postcolonial Kenya turned his son into an American patriot. In his memoir, Obama describes the way tribalism ruined his father’s life. The senior Obama, an ambitious young government reformer, found himself on the wrong side of an ethnic divide in his newly liberated country, and this became his undoing. The poison of division, his son concluded, was for other countries, but not for America.

In an interview I conducted with Obama last year, he said, “It is literally in my DNA to be suspicious of tribalism. I understand the tribal impulse, and acknowledge the power of tribal division. I’ve been navigating tribal divisions my whole life. In the end, it’s the source of a lot of destructive acts.”

The American idea, Obama has suggested, is the best antidote for parochialism and sectarianism. Its power was demonstrated, in his view, by the election—twice—of a biracial senator with roots in Kenya and Kansas, a Muslim name, and a proud African American wife.

Obama is not an unalloyed idealist. He has complicated feelings about the nature of humanity, and harbors few illusions, in particular, about the moral systems that govern many other countries. But he has always seemed sincere in his belief that America is a place that possesses a unique capacity to become better, and then better again. “The arc of the moral universe is long, but it bends toward justice,” he often said, quoting Martin Luther King Jr., but he really meant that America’s arc bends toward justice.

And then came Donald Trump.

Shortly after the election in November, I spoke with my friend and colleague Ta-Nehisi Coates, the author of this issue’s extraordinary cover story. The story refracts Obama’s improbable presidency through the prism of race. It is built on hours of conversation between the two men, and on years of hard thinking by Coates.

Coates and the president have been in something of an argument; Coates has written in these pages that Obama’s faith in the underlying fairness of America’s social and political institutions is unearned, and Obama appears to believe that Coates is at times too closed to the possibility of progress.

I told Coates after the election that he seems to have the upper hand in the argument, at least for now. Trump was not propelled to the White House solely by the forces of racial reaction. And yet an important and resentful tribe has opened a fissure in American society, and the chief of this tribe—who traffics in racial invective and who long cast Obama as a foreign-born threat to the American way—has broader appeal than I imagined. One does not have to be an apocalyptist to sense a curving-back of the arc of justice.

But when we spoke, Coates told me that we are not moving inexorably backwards. In his latest book, Between the World and Me, he argues that the arc of the universe bends, in fact, toward chaos. He doesn’t believe the U.S. is having a good moment, but he also doesn’t believe that he is right and Obama is wrong about the ultimate trajectory of history.

“History is an indifferent force,” Coates said. “I thought Donald Trump was a comet that was narrowly missing Earth. But the comet hit.” Still, he went on to say, we are not on an inescapably revanchist pathway. “Obama’s victory in 2008 was also a sign of chaos, of disruption,” he said. “Who knows? Right now there could be someone working in Obama’s White House who will turn out to be a major force 20 years into the future.”

We do not yet know the truest meaning, or the deepest consequences, of the rise of Donald Trump. And we do not yet understand what his rise will mean for the legacy of America’s first black president, or for the future of relations among the races.

The Atlantic, however, is committed to understanding the meaning of these events, just as it has been committed to discerning the meaning of the Obama presidency, and just as it has been committed to advancing the cause of the American idea. This magazine was founded in 1857, at a time of immense fracturing in this country. The Atlantic is at its best in difficult times, when the task of explaining America to itself, and to the world, is most crucial. In this new age, we are redoubling our efforts to do this important work. Ta-Nehisi Coates’s latest cover story is only one manifestation of our promise to readers.