What does it mean to be an “American”? This question has taken on renewed significance in light of the recent dispute between the president and the Squad (Congresswomen Ilhan Omar of Minnesota, Alexandria Ocasio-Cortez of New York, Rashida Tlaib of Michigan, and Ayanna Pressley of Massachusetts).

The good news is that in spite of the heightened divisions in the era of Trump, the American melting pot is still alive and well. One in five newlyweds is marrying someone of another race, according to a recent Pew report. And economists Brian Duncan and Stephen Trejo, who studied the process of assimilation by Latinos, have concluded that by the third or fourth generation, many have intermarried and stopped self-identifying as Latino (most call themselves “white,” as have previous generations of Irish, Italians, and other ethnic groups).

The story is less successful in regard to Americans of African descent, largely because of the complex legacy of slavery (although even here, Pew notes that intermarriage is breaking down that particular barrier). Other recent studies indicate that “assimilation success was larger for those culturally closer to native whites. [These patterns] are consistent with a framework in which changing perceptions of…[racial threats] among native whites lower the barriers to the assimilation,” both racially and linguistically.

Indeed, apart from Spanish, all the other diaspora languages have become minor and ephemeral (there was far more linguistic diversity in the United States in 1900).

Why, then, are we constantly given this misleading picture of the melting pot being replaced by a “salad bowl,” where ethnicities are hyphenated and divisions are accentuated? Additionally, why do both political parties continue to premise their electoral strategies on the anachronistic belief that voters will continue to self-identify as specific ethnic groups whose voting preferences and ideologies remain set in stone?

These tactics are in large part the product of social policies launched during the 1960s. One of these is racial gerrymandering (which ostensibly rewards people who claim to belong to an unassimilated group by ensuring their political representation, but actually diminishes political competition for their votes and often leads to these groups’ support being taken for granted by one party and dismissed by the other).

Others are the effects of the 1965 Immigration Reform Act, and affirmative action programs that have failed to incorporate class-based criteria, dividing natural working-class allies on the basis of race. The latter in particular led to a problem to which Jesse Jackson alluded during his 1988 campaign for the presidency when he was asked, “How you are going to get the support of the white steelworker?” He replied: “By making him aware he has more in common with the black steelworkers by being a worker, than with the boss by being white.”

Unfortunately, economic self-identification and class consciousness become harder to achieve when so many policies remain race-centered. As the last 50 years have illustrated, this has often resulted in hugely divisive outcomes, even outside the Deep South. It’s also obscured the more recent phenomenon of economic inequality and concomitant wage stagnation that the middle and working classes have experienced over the past 40 years (which is not solely a function of race). And while income inequality has increasingly come into focus as we approach the 2020 election, it is also the case that issues such as busing, race, gerrymandering, and immigration are again becoming factorsto a degree not seen for decades.

The ongoing controversies associated with affirmative action policies are still being debated some 50 years on (including during the confrontation between former vice president Biden and Senator Kamala Harris in the last Democratic candidates debate)—but less so the fallout from the Immigration and Nationality Act of 1965. While this legislation had the virtue of explicitly prohibiting discrimination on the basis of race, sex, nationality, place of birth, and place of residence in the government’s decisions to issue immigrant visas, its authors did not anticipate that its prioritization of family reunification (which replaced racial quotas) would lead to a massive influx of poor people from Latin America.

Trump has exploited this issue. But the Democrats’ reticence in acknowledging any serious flaws in the current system (especially with regard to border enforcement) indicates their changing political calculations—a byproduct of the demographic changes wrought by the 1965 law. This has induced a different approach to immigration from the days of the U.S. Commission on Immigration Reform (aka the Barbara Jordan Commission) during the 1990s. Jordan, a Democrat, sought to achieve an immigration policy that balanced the economic needs of the United States with the goal of “protect[ing] U.S. workers against unfair competition from foreign workers, with an appropriately higher level of protection for the most vulnerable in our society.” By contrast, as Ross Douthat has argued, the current focus of Democrats is “decriminalizing illegal entry and extending public benefits to undocumented immigrants,” which may well incentivize additional illegal immigration.

Why propose it? For one thing, the ballooning Latino population, expanded by immigration, has led some analysts, such as Steve Phillips of the Center for American Progress, to make the case that the Democratic Party should prioritize these voters over white working-class workers (who gravitated toward Trump in 2016). In his book Brown Is the New White, Phillips concludes, “The concerns of people of color should be driving politics today and into the future.”

To a large degree, what Phillips advocates is already driving Democratic politics, as one could see in the recent primary debates. The “Hispanization” of the United States explains the Democrats’ advocacy of abolishing Immigration and Customs Enforcement (ICE) and reticence to limit the access of undocumented immigrants to public education and health care.

So why haven’t the Republicans fought back by appealing to assimilated working-class blacks and Latinos of the outer suburbs? Some, such as newly elected Josh Hawley, Marco Rubio, and former senator Rick Santorum, are trying to move the GOP in this direction. But for the most part, these “blue collar” advocates are still minority voices in their party, which (like the Democrats) remains captive to its own corporate interests, along with another part of its core base, white Southern evangelicals.

What is most interesting about the Pew poll, as well as the research of Professors Duncan and Trejo, however, is that assimilation is rendering both parties’ historic electoral calculations increasingly irrelevant. Ongoing and, indeed, rising assimilation via intermarriage suggests that demography will ultimately undermine both Democratic identity politics and Republican religious politics, through both migration to the South and the rapid collapse of organized Christianity. Millennials in particular seem to eschew self-identification along strict ethnic and religious lines.

Indeed, despite being one of the earliest proponents of the “emerging Democratic majority” thesis, author and political commentator John Judis now argues:

Whiteness is not a genetic category, after all; it’s a social and political construct that relies on perception and prejudice. A century ago, Irish, Italians, and Jews were not seen as whites. “This town has 8,000,000 people,” a young Harry Truman wrote his cousin upon visiting New York City in 1918. “7,500,000 of ’em are of Israelish extraction. (400,000 wops and the rest are white people.)” But by the time Truman became president, all those immigrant groups were considered “white.” There’s no reason to imagine that Latinos and Asians won’t follow much the same pattern.

Judis, therefore, now rejects “demographic determinism.”

Unfortunately, we may have to wait a few more elections before the two parties respond more aggressively to these assimilationist trends. Because of racial gerrymandering, each party has its base in safe districts—for Democrats, the big cities where 30 to 40 percent are foreign-born, and for Republicans, the white exurban South and Appalachia.

So far, both parties are simply reaching out to the mixed-race working-class melting pot areas without rethinking their post-’70s base strategies. Indeed, they are doubling down on them, hoping that mobilizing their urban or Southern bases will enable them to minimize their outreach to the new melting pot that is emerging in many parts of the country. In the short term, that will perpetuate today’s divisions and potentially reelect Donald Trump. But longer term, changing demographics suggest a very different, and less divisive, sort of politics.

Marshall Auerback is a market analyst and a research associate at the Levy Economics Institute at Bard College.