The Trayvon Martin shooting was hardly in the national consciousness before fault lines emerged around the case. Was Martin as innocent as he seemed? Did Zimmerman fear for his life? Did Martin provoke the incident? Was Zimmerman a racist?

Perhaps most controversial among all of these was the question of identity. Yes, Trayvon Martin was black, but is Zimmerman white? For Martin’s sympathizers, the answer was yes. For Zimmerman’s, the answers ranged from “it doesn’t matter” to he “is actually a Hispanic nonracist person who acted in self-defense.”

In their early reports on the case, both CNN and the New York Times labeled him “white Hispanic,” sparking thunderous condemnation from right-wing critics. At Fox News, contributor Bernard Goldberg accused the Times of race-baiting. “I guarantee you that if George Zimmerman did something good—if he finished first in his high school graduating class when he was younger—they wouldn’t refer to him as a white Hispanic, he’d just be a Hispanic,” he wrote. Likewise, National Review’s Jonah Goldberg blasted several news outlets for “playing the race card” with the term. And in typical paranoid style, Breitbart’s Ben Shapiro accused CNN of “labeling Zimmerman a ‘white Hispanic’ in order to maintain the false narrative that the killing was race-based.”

For good reason, this debate—whether the half-Peruvian Zimmerman was “Hispanic” or “white”—was quickly overshadowed by the activism and acrimony around Martin’s killing. But it’s not unimportant, as it reflects the tension and confusion over race in a changing America and offers a 21st-century spin on one of the oldest questions in American life: Who is white? This debate is useful to keep in mind as we sift through the information in the Pew Research Center’s new—and massive—look at America’s shifting demographics.

According to Pew—and echoing the results in the last census—the United States is just a few decades away from its demographic inflection point. Come 2050, only 47 percent of Americans will call themselves white, while the majority will belong to a minority group. Blacks will remain steady at 13 percent of the population, while Asians will grow to 8 percent. Hispanics, on the other hand, will explode to 28 percent of all U.S. population, up from 19 percent in 2010. Immigration is driving this “demographic makeover,” specifically the “40 million immigrants who have arrived since 1965, about half of them Hispanics and nearly three-in-ten Asians.”

But the thing to remember about the Hispanic category, for instance, is that it contains a wide range of colors and ethnicities. In the United States, Hispanics (or more broadly Latinos) include Afro-Brazilians, dark-skinned Puerto Ricans, indigenous Mexicans, Venezuelan mestizos, and European Argentinians, among others.

To say that America will become a majority-minority country is to erase these distinctions and assume that, for now and forever, Latinos will remain a third race, situated next to “non-Hispanic blacks” and “non-Hispanic whites.” But, as the Zimmerman controversy illustrates, it’s not that simple.

American racial categories are far from fixed, and who counts as white is extremely fluid. “A hundred years ago,” writes Ian Haney López in Dog Whistle Politics, “firm racial lines elevated Anglo-Saxons over the supposedly degenerate races from southern and eastern Europe.” For a large chunk of the 19th century—and a good deal of the 20th—America’s intellectual energy was devoted to policing the boundaries of “whiteness.” Race “scientists” like William Z. Ripley measured human skulls and examined living standards to delineate the “races” of Europe, linking head shape to supposedly racial qualities like beauty and intelligence. Others used these supposedly objective factors to exclude a variety of different groups—Irish, Italians, Eastern Europeans—from the American racial category, envisioned as a white person of British or German stock. “White race taxonomy,” writes Nell Irvin Painter in The History of White People, “was evolving into notions of immigration restriction and eugenics.”

Over time, however, as new immigrants entered the country and old ones gained access to levers of power and influence, the boundaries grew to include them. As Painter explains, “In their penury and apparent strangeness, the new [Southern and Eastern European] immigrants after 1880 made Irish and Germans immigrants and … their more prosperous, better-educated descendants seem acceptably American.”

It’s hard to say history is repeating itself—the circumstances of the early 21st century are vastly different from those of the late 19th—but the current period does seem to rhyme with the past. Over the last 50 years of large-scale Latino and Asian immigration, we’ve seen waves of anti-immigrant hysteria (Proposition 187 in California and the minutemen along the Mexican border), attempts to keep high-achieving immigrants and their children out of elite institutions, and intermarriage leading to assimilation—one of the most famous comedians in the world, Louis C.K., is half-Mexican, but to most Americans, he’s just a white guy.

Which is to say that, before we begin to say anything about our majority-minority future, we have to consider the ways in which our existing social dynamics and racial boundaries will change in response to the demographic shift.

Going forward, will white Hispanics see themselves as part of a different race—light-skinned but distinct from whites—or will they see themselves as another kind of white? Will the government treat them as white in its forms and surveys, and will so-called traditional white Americans understand them as such? What about the children of mixed marriages? As Pew points out, we live in an age of intermarriage. More than 15 percent of new marriages are between partners of different races, and the large majority of them are Hispanic and Asian “out marriage” to whites. Will these children retain a racial identity, or will they join the vast tapestry of American whiteness?

These are critical questions, since—in a country where white Hispanics are just white, and Asians intermarry at high rates—the white population of the United States could stay steady or actually grow.

Of course, not all Hispanics and Asians will enter the white mainstream. We don’t see them in popular culture, but there are sharp racial and class divisions in both groups. Low-income, dark-skinned Latinos and Pacific Islanders, for instance, face prejudice, racism, and a huge array of socio-economic challenges. And going forward, that might stay the same, as their fair-skinned, more affluent counterparts “become” white. Or, put another way, now might be the last time we have a public debate over the whiteness of a figure like George Zimmerman. To Americans of 2050, the answer would be obvious: “Of course he is.”

Pew ends its description of our changing demographics with a small rhetorical flourish: “We were once a black and white country. Now, we’re a rainbow.”

Or are we? After all, while we see the 19th century as a world of blacks and whites, that wasn’t true for Americans at the time. They saw their United States as diverse as we see ours—a hodgepodge of races and ethnicities, with blacks as the insoluble element. The difference was their construction of race, which placed various Europeans on a convoluted hierarchy of racial difference.

Our hierarchies are a little flatter, and—in public life, at least—we aren’t as obsessed with racial boundaries. But both still exist, and they take a familiar form: whites at the top, blacks at the bottom. The future could make a collection of minorities the majority in America, or it could broaden our definition of white, leaving us with a remix of the black-and-white binary. A country where some white people are Asian, some are Hispanic, and the dark-skinned citizens of America—and blacks especially—is still a world apart.