It's a day that will be indelibly burnished on America's political memory: June 16, 2015, when Donald Trump descended on an escalator from the marble splendor of his Trump Tower penthouse — with his supermodel wife ahead of him, Neil Young's "Rockin' the Free World" blasting at 11 from the speakers — to tell all the little people waiting on the ground that he was running to be America's 45th president.

The idea of a Donald Trump presidency had been the stuff of speculation and satire for three decades — the assumption being he'd run on his alleged business savvy, even after those three decades had revealed his CEO acumen was more hype than reality. But although he'd displayed a new political instinct at the dawn of the 2010s — with a deep dive into Barack Obama "birtherism" that appealed to worst instincts of the burgeoning Tea Party movement — no one was really ready for what came out of his mouth that late spring day.

Trump said Mexico was sending its worst people, murderers and rapists, to America as immigrants, and then he added that as president he'd build a "great, great wall on our southern border, and I will make Mexico pay for that wall." To many pundits, the alleged billionaire's words that day pegged him as too extreme for the Oval Office. But to millions of voters in neglected Rust Belt towns and surrounding farmland, those ugly chords were sweeter music than any riff from Neil Young's faded guitar.

Trump's announcement launched a mystery that's lasted 14 months into the most unlikely presidency in American history. Where did the ideas that animated the candidate's packed rallies — and juiced voter turnout in Rust Belt states like Pennsylvania, Michigan, Wisconsin and Ohio — come from? "Build the wall!"? "Drain the swamp!"? "Crooked Hillary!"? "Deep state!"? Defining immigrants as violent gangs or murderous thugs? Painting American's urban neighborhoods as crime-infested ratholes.

In a stunning week of revelations, we now know the answer. The core messages of the president's underlying xenophobia and racism that animated his base didn't emerge from the mind of "very stable genius" Trump (despite a long life of troubling racial attitudes). Instead, the nonstop undercurrent of hate toward The Other in American life was focus-grouped, computer-coded, deliberately amplified by a new ultra-right-wing media echo chamber and then targeted with cruise-missile precision at the handful of states that Trump won by roughly 100,000 votes to grab the Electoral College.

At its blackened heart, it turns out, are the two ugliest words to emerge in U.S. politics in the 21st century: "Race realism."

There's nothing real, or factual, about "race realism." To the contrary, it's the rank, old-school racial stereotypes about black- and brown-skinned people that once animated slaveholders, the KKK or the White Citizens Councils of yesterday, dressed up in Adidas sneakers and a hip-hop T-shirt instead of a white robe. What we've learned these past few days is a kind of a dystopian nightmare: That Team Trump, led by its multimillion-dollar data gurus Cambridge Analytica (CA) and the president's former propaganda minister, Steve Bannon (with a still mysterious assist from Russian trolls), used the modern techniques of information warfare — and hijacked data from Facebook — to inject a virulent strain of thinly disguised white supremacy to elect an American president.

We know now how this worked, thanks to a courageous insider, Christopher Wylie, who has revealed the secrets of Bannon and Cambridge Analytica as a whistleblower. Much of the attention has focused, understandably, on what you might call the "garbage in" aspect of CA's work for Trump, the fraud and trickery that was used to gain 50 million Facebook profiles and use "psychometric" profiling to play on voters' fears and prejudices. There's been way too little focus on the "garbage out" — what those messages were and how they were crafted.

Wylie told the Washington Post the backstory of how he, Bannon, a financier then running the right-wing Breitbart News, ultra-conservative hedge-fund billionaire Robert Mercer and a cyber-warfare expert named Alexander Nix came together in 2014 to launch Cambridge Analytica. The whistleblower said it was Bannon who was calling the shots and who was particularly interested in one particular issue: How to win over young conservative white males who were staying home on Election Day. The new start-up convened focus groups to find out.

The Post reported that "these voters responded to calls for building a new wall to block the entry of illegal immigrants, to reforms intended to 'drain the swamp' of Washington's entrenched political community and to thinly veiled forms of racism toward African Americans called 'race realism,' he recounted."

Bizarrely, Trump himself seemed to acknowledge in a tweet this Thursday morning that the messages crafted by CA were critical to his victory.

What's more, Trump also admitted this week at a fund-raiser that "drain the swamp" was a phrase that was given to him — by whom exactly, he didn't say, although the circumstantial evidence points to Bannon and CA — and that he didn't like it until his predominantly white rally crowds went wild:

High-tech political "psy-ops" work, apparently. Trump has in the past voiced similar surprise at how well the "build the wall" meme succeeded on the campaign trail, although Wylie has said the idea of a physical quarantine played right into the psychological fears of those voters most disturbed that America is becoming increasingly non-white. Likewise, CA's now-suspended CEO Nix was caught on tape bragging how his firm used high-tech to "weaponize" the phrase "Crooked Hillary."

But arguably the most disturbing aspect of all this is the push for "race realism." I'd never heard that exact phrase before this week, and there's a good chance that you haven't either — unless you spend a lot of time on websites or message boards appealing to the white nationalists who've tried to re-brand themselves as "the alt-right."

"Race realism," it seems, is a modern update on centuries of pseudo-science (the eugenics movement of the earliest 20th century, for example). It's also been called "scientific racism," and you probably won't be shocked to learn this debunked mumbo-jumbo was also a key philosophical underpinning of Nazi Germany and its propaganda minister, Joseph Goebbels.

Indeed, "race realism" today is a core value of the yahoos you witnessed marching with their Home Deport tiki torches in Charlottesville, spread by the likes of "Hail Trump" white nationalist ally Richard Spencer as well as the random neo-Nazis who salute the new president and pseudo-academic journals with names like American Renaissance. There's always been what the historian Richard Hofstadter called "the paranoid style in American politics", but Bannon and Trump have made that mainstream, with dangerous omens for U.S. democracy.

Remember, Bannon in the run-up to teaming with Trump was a double-edge sword, using the data he gained from his role at Cambridge Analytica not only to bamboozle voters through Facebook messages and "fake news" but also as the editor of his own rising website, Breitbart News.  Under Bannon's leadership, Breitbart launched a special section called "Black Crime" that pandered to its readers' foulest stereotypes about African-Americans and lawbreaking. (You can see some examples of what the Southern Poverty Law Center has called "a white ethno-nationalist propaganda mill" here.)

Interestingly, many of the posts now linked to the Russian troll farm which was indicted, along with some of its key players, by special counsel Robert Mueller, also worked hard to drive up racial divides in America, using Facebook and even staged events to stir up both left-leaning black activists and the conservatives who most despise them.

In the summer of 2016, when few experts gave Trump any chance of winning the general election and after Robert Mercer and his billions signed on with the GOP nominee, Bannon was abruptly named the CEO of the Trump campaign. It was a short time later that Trump began talking about race on the campaign trail, in what was ostensibly a pitch for black votes. But what a bizarre pitch it was.

"You're living in poverty, your schools are no good, you have no jobs, 58 percent of your youth is unemployed." Trump told a rally in September 2016. The ostensible message was, "What the hell do you" — African-Americans — "have to lose" by voting for the Republican, but the words seemed instead to reinforce the stereotypes of "race realism." There were virtually no blacks in the audience that day. The rally was held in Dimondale, Michigan, a small town (92.7 percent white) near Lansing — the kind of place where jacked-up turnout helped Trump gain stunning narrow victories that November not just in the Wolverine State but the other Rust Belt states where he (and Cambridge Analytica) had targeted those young white male conservative voters.

Even now, as president, Trump falls back on "race realism" when he gets into a political jam — calling any black athlete who protested social injustice during the National Anthem a "son of a bitch" (in Alabama, the state that gave us George Wallace and Selma's "Bloody Sunday") or labeling a leading African-American critic, Rep. Maxine Waters. "a low-IQ individual." He's determined to hold his base together. And he's got the data to prove that racism works.

It's time to see this noxious phenomenon — the spirit of yesterday's cross burnings, sparked by today's internet electrons of Facebook's friendly facade — as what it is, as not just some background noise but as the cornerstone of what elected Trump, and what powers his wayward presidency. That's why it's so important for Mueller (and perhaps a Democratic House in 2019) to get to the bottom of Bannon's work with CA, Breitbart and Trump and what crimes, if any, were committed in spreading this poison. We can't outlaw the notions of white supremacy, but we can punish the people who used fraud to inject these odious ideas into our body politic.

Because "race realism" isn't an actual thing. It's just real racism.