If there was one silver lining to President Trump’s election, it was supposed to be this: Those who voted for Trump because of, rather than despite, his demonization of Muslims and Hispanics; who fear a “majority minority” America; and who wax nostalgic for the Jim Crow era were mostly old white people.

Which meant they and their abhorrent prejudices would soon pass on — and be replaced by generations of younger, more racially enlightened Americans.

The white nationalist rally this past weekend in Charlottesville, Va., shows that this is a myth. Racist grandpas may be dying out, but their bigotry is regenerating in today’s youths.

Yes, there were swastika-tattooed, Ku Klux Klan-hooded people in their 50s on the streets of Charlottesville. The most chilling photos, however, show hordes of torch-bearing, fresh-faced, “fashy”-coiffed white men in their teens and 20s.

Some marchers in this youth brigade are still students, one the leader of his campus chapter of the College Republicans. And some did more than march.

The driver accused of murdering counterprotester Heather Heyer and injuring 19 is a 20-year-old white man.

He would of course not be the first radicalized young white man to commit an act of domestic terrorism. There was the then-21-year-old white male who murdered nine African Americans at a Charleston, S.C., church in 2015, and the 28-year-old white Baltimore man who in March allegedly rode a bus to New York in search of black men to kill at random.

A recent Joint Intelligence Bulletin, obtained by Foreign Policy magazine, details plenty of other attacks perpetrated by young white-supremacist men.

The public faces of the white supremacist “alt-right” movement are likewise skewing younger. David Duke is still around, but as a charismatic figurehead he has mostly been displaced by the likes of 39-year-old Richard Spencer, 26-year-old Matthew Heimbach and 29-year-old Tim “Baked Alaska” Gionet.

These are not people whose backwardness we can write off as an unfortunate product of their time.

That is, we’re not talking about young white Americans whose happy formative years took place in a world with (de jure) school segregation, redlining, antimiscegenation laws and phrenology.

If any had family who fought for the Confederacy, they’ve been dead for at least a century. No one is telling them about the good ol’ days on the plantation.

If anything, parents of the Charlottesville rally-goers have professed ignorance or repudiation of their children’s odious beliefs.

So why are Millennials, of all people, at the forefront of the small but highly visible resurrection of neo-Nazism?

Some seem to be reactionaries, essentially trolls who may or may not truly believe the anti-Semitic and racist bile that they meme and share to get a rise out of the left. If youthful rebellion in the 1960s meant embracing free love, peace and equality, then today — at least for anti-anti-Trumpers — it is about promoting hatred and structural inequity.

Others may genuinely wish to burn the whole system down.

It is a flawed system, after all, one whose recent financial crisis irreparably scarred Millennials’ economic prospects. Most antiestablishment Millennials have drifted toward leftist populist alternatives, but some have sorted into the opposite extreme. For right-wing populists, the key flaw with the system is not that it allows the rich to hoard all the money, but that it privileges undeserving minorities at whites’ expense.

Extreme ideology and iconography may also no longer carry the same political baggage. Just as “socialism” is not a toxic word to people who came of age after the Cold War, perhaps aligning with Nazis no longer seems evil for those so far removed from World War II.

More significantly, the presumption that Millennials are uniformly more progressive than earlier generations is false.

Millennials overall are more racially tolerant than earlier generations — but that’s because they are less likely to be white. White Millennials exhibit about as much racial prejudice, as measured by explicit bias, as white Gen Xers and Boomers. Yet even young people know that overt racial animus is socially frowned upon.

At least, they did, until the 2016 presidential campaign. Perhaps it’s no wonder that some self-aggrandizing young white men heard a siren call in all those dog whistles: Tomorrow belongs to them.

© 2017, Washington Post Writers Group

Email: crampell@washpost.com. Twitter: @crampell.