One evening shortly before Election Day, I found myself waxing philosophic with a good friend over the differences between "tribes" and "empires."

It seemed my friend — a professional political junkie like myself, only more liberal — had been musing about what makes for a stable, peaceful society. In light of the convulsive presidential campaign of 2016, he'd begun to think that maybe close-knit, homogenous communities, bound together by common ethnicity, religion, traditions, etc., make more sense than large unions embracing diverse populations.

We agreed that today's world scene features numerous multicultural political communities at risk of falling to pieces — from the European Union, rocked last summer by Britain's "Brexit" vote; to the United Kingdom itself, threatened by a deathless Scottish independence movement; to a half dozen artificial multiethnic, multisectarian countries in the Middle East.

And then there's the case that was really on our minds — the case of the USA, history's "exceptional" hodgepodge, melting pot success story.

Or so we thought.

Whatever else he does, Donald Trump has already repealed and replaced conventional political wisdom in America. His election may be the most astounding personal — virtually single-handed — political victory in modern history.

Enormous powers within the political establishment, in both major political parties, stood against Trump. The bulk of big-money special interests stood against him. And virtually the entire mainstream media — once it got over enjoying too carelessly the nervous breakdown he caused establishment Republicans during the early primaries — turned against Trump with an utterly unprecedented and nearly unanimous onslaught of hostility.

Pundits, prominent and obscure, fumed and resigned from the GOP. Newspapers, prominent and obscure, published special "dis-endorsements," sometimes multiple ones, all about the reasons Trump was unworthy of election.

One distinguished Midwestern daily even called, barely a month before the vote, for Trump to drop out of the race.

None of it mattered. If the press felt duty-bound to oppose Trump with all its might, even at the risk of confirming the charge not merely of a liberal bias but of consciously taking sides — it soon compounded matters by proving itself naive and out-of-touch to boot. Supposing that the dragon had been slain, precious few analysts or pollsters saw Trump's electoral tsunami coming.

What Trump uncannily understood so much better than political and media experts was precisely that all of America remains an empire, not a tribe. Deep and durable fault lines still fragment even its (still) majority white population.

Yes, there's been endless discussion for years of the "polarization" of politics in our time. But mainly what we've been talking about was a more inflamed debate between liberal and conservative elites in media, government and academic circles. These influential insiders may differ intensely on policy and compete bitterly for political clout. But they share a culture, with similar levels of education and affluence, comparable tastes and lifestyles.

Trump spoke to, and for, an altogether different American culture long locked outside the halls of influence — a white-working-stiff culture today's leadership class simply doesn't seem to know. It was hard for establishment insiders to conceive how so many Americans could support a candidate so outlandishly coarse and careless.

But it turns out that in that frustrated, alienated working-stiff culture, brash, ungraceful, tough-guy rhetoric; unapologetic suspicions of outsiders, and unrelenting hostility to the smug bigshots who run things can make a paladin look and sound like "one of us" — like somebody fearless enough to name their fears, even if he got called names for doing it. Like somebody just crazy enough to shake things up but good.

Seldom has a book proved more prescient than sociologist Charles Murray's "Coming Apart: The State of White America, 1960-2010," published four years ago. Murray showed with startling statistical clarity that non-college-educated white America ("Fishtown," he called it) shared a common culture a half-century ago with college-educated white America ("Belmont," in Murray's telling). But the two groups share a common culture no longer, he wrote.

Ironically, to greatly simplify Murray's story, residents of Fishtown still believe in old-fashioned values but increasingly lead troubled, disordered, threadbare lives. Belmonters prosper, leading comparatively old-fashioned lives while promoting avant-garde social ideas.

Trump emphasized the economic grievances of Fishtown, but he also spoke forcefully against abortion and against "political correctness" in all its forms. It is hard to doubt that the simmering frustration that boiled over last week was partly fueled by the cultural left's pushing its advantages too far too fast in recent years on such cultural issues as same-sex marriage and transgender bathroom rights, while tolerating little dissent even from those with religious objections to the new order.

At all events, it seems clear that groupthink in "Belmont" was strong enough to conceal from the elite what Trump plainly saw — how passionately Fishtowners disagreed with one feature or another of the current regime (and how many Fishtowners there still were).

Way back in 2012, in the wake of President Obama's re-election, much expert opinion agreed that the Republican Party needed a soul-searching reinvention. The GOP might never win a presidential election again, it was widely said, unless its tone and platform became more congenial and understanding toward minorities, particularly Latinos. Well.

This year, reminded that this American empire houses many lost tribes with legitimate gripes, maybe it's Democrats who need to get to know a sizable minority group they've been overlooking.

D.J. Tice is at Doug.Tice@startribune.com.