Universal theories can have a certain tidy attraction. In science, they can result in revolutionary breakthroughs — Albert Einstein’s Theory of Relativity comes to mind. In the messy realm of human affairs, however, universal theories have a tendency to fall apart.

Ruy Teixeira, of the leftist Center for American Progress, provides a textbook example of a brilliant man developing a theory for determining the course of politics in America. In the 2002 book, The Emerging Democratic Majority, Teixeira and coauthor John Judis asserted their theory that minority voters who prefer Democrats grow as a share of the electorate by 2 percentage points every four years. This demographic shift would inevitably lead to Democrats’ long-term political dominance.

Practically speaking, this would result in the entire nation becoming like today’s California — a one-party bastion of modern leftism.

Now, Teixeira is out with an important essay titled “Demography Is Not Destiny,” which shows all is not on track with his prognostications. In a phrase evocative of a nomenklatura in charge of doctrine, Teixeira warns that the vanguard of the proletariat has indulged in a “dangerous misunderstanding” of his theories. The diverging problem, argues Teixeira, stems from Barack Obama’s 2012 victory and reelection, combined with the “bowdlerization” of his work at the hands of James Carville in his book 40 More Years — How Democrats Will Rule the Next Generation.

The cadre’s fatal error was becoming so convinced of their eternal triumph that they forgot that winning national elections still requires a sizable portion of the white working class — at least for the near future. This misled victorious leftists to assume that all they needed to do was to mobilize “black, Hispanic, (and) Asian” voters along with “unmarried” or “highly educated” women while taking advantage of a set of “interrelated social, economic and demographic changes, including the growth of minority communities and cultural shifts among college graduates.”

This unfounded optimism, Teixeira mourns, resulted in a “decade-long electoral disaster” as working-class whites grew hostile to the ideologies of “intersectionality” and critical race theory that slowly spread out from campuses.

Theorists and promoters of tribal politics were shocked that working-class whites, many of whom voted for Obama twice, would be repelled at the politics of victimhood and group identity. This shock metastasized into anger in 2016, explaining “Hillary Clinton’s infamous statement that half of Trump’s supporters belonged in a ‘basket of deplorables’ — the kind of gaffe that reveals what its speaker really thinks.”

Not to fear, though — Teixeira still believes in the inevitable power of numbers:

Demographic changes really do favor Democrats — to an extent … The party should proudly emphasize the ability of government to improve the lives of ordinary Americans. But its governing ideology could not present itself as standing in radical opposition to the country’s founding values.

To win, Democrats simply have to try not to appear anti-American or too crazy, while riding “a broader trend towards the Democratic Party among the growing professional class, with its permissive social values and support for active government … coming together in dynamic metropolitan areas rooted in the emerging post-industrial economy.”

There are a few fundamental problems, however, even with Teixeira’s revised thesis. On the whole, Teixeira still doesn’t seem to grasp that demographics both shape and are shaped by politics. It’s not a “one-way” relationship, it’s symbiotic.

First, and most obviously, politics isn’t a static phenomenon. Just as working-class whites shifted their allegiance from Obama to Trump in 2016, so too are other segments of the American electorate subject to evolving political preferences. For more than two generations after the Fifteenth Amendment extended the right to vote to all citizens, regardless “of race, color, or previous condition of servitude,” black Americans voted Republican between 1870 and 1936 (when they could).

Second, demographics are malleable — it’s not at all as neat and clean as the bean counters at the Census Bureau would have us believe, and Americans are increasingly marrying across racial and ethnic lines. By 2015, 17 percent of all new marriages featured spouses of different racial or ethnic groups. For the most part, the children resulting from these unions will be classified by the U.S. Census as “minorities.” This presents a misleading demographic picture.

So, what are children born of two U.S. citizens, a mother of Chinese ancestry and a father whose parents emigrated from Ethiopia? The correct answer is, of course, they’re Americans. But for leftists like Teixeira, they’ll grow up to be part of a group with certain political behaviors somehow hardwired by the circumstances of the journey to America taken by their forebearers.

Beyond the issue of demographic classification, there’s a more intangible factor at play: identity. My 95-year-old father-in-law lives in my home. His parents emigrated from Sicily at the turn of the last century. The press described the new arrivals as “swarthy,” while on the streets they were often called “n—- wops.”

He describes entering kindergarten in upstate New York and not being able to speak a word of English. Fifteen years later, he was in the U.S. Navy in France in a place called Normandy. He still likes to sit in the sun, and his skin is darker than most Texans classified as “Hispanic,” yet he’s a “white, non-Hispanic.” If you ask him what he “is,” he’d look at you with puzzlement and then answer, “I’m an American.”

The process of becoming American may take longer now than in the past, as a segment of elites see an advantage in political Balkanization. But it still occurs. We see this in Texas, where large segments of middle-class Hispanic residents, many with roots stretching back to the very founding of Texas, view themselves as “Texans” or “Americans” rather than some sort of hyphenated variant. This also manifests in voting behavior, with Hispanics leaning more to the right in Texas than at the national level.

In California, however, this is not so much the case. There, immigration from Mexico is often more recent than in Texas and more frequently from the poorer regions. The political implications of this undermine Teixeira’s thesis.

There remains another challenge in attempting to win political power by appealing to “tribes”: math. Any system aimed at electoral dominance by dividing people into groups then using the power of government to redistribute resources from a disfavored group to the favored group will soon find itself out of groups to take resources from.

We see this today in California with state college admissions. In a drive to include more minorities, colleges are running out of white, non-Hispanic students to exclude and therefore must, mathematically, start to exclude qualified Asian students. What happens to that reliable bloc of the electorate then?

Lastly, Teixeira’s vision of an emerging majority “coming together in dynamic metropolitan areas rooted in the emerging post-industrial economy” is crashing against the unyielding reality that leftist politics — really, any utopian organizing principle — cannot work in the real world, at least, not for long.

The woke legions of Antifa looting and burning down the urban cores while calling for “defunding the police” may have an unintended electoral effect on Teixeira’s unmarried and college-educated women. Fear does that to people. So long as the new left’s “permissive social values” include the destruction of property and looting, the acrid smell of the burning local Apple store may cause a shift in political priorities for urban residents who, just a year ago, took freedom from fear for granted.