Donald Trump's presidential candidacy is unique and remarkable in many ways. Never before has someone with no experience in government, not even a shred of understanding of public policy, and little in the way of an organized campaign done so well. Trump has been leading the Republican race for nearly five months, and shows no sign of faltering.

And here's one other way it's remarkable: After decades of rhetorical evolution from Republicans on matters of race, Donald Trump is now running the most plainly, explicitly, straightforwardly racist campaign since at least George Wallace's third-party run in 1968, and maybe even Strom Thurmond's in 1948.

All the way back in 1981, Republican strategist Lee Atwater explained how his party's candidates had changed the way they talked about race and government to white voters over time. "You start out in 1954 by saying, 'Nigger, nigger, nigger,'" Atwater said. "By 1968 you can't say 'nigger' — that hurts you, backfires. So you say stuff like, uh, forced busing, states' rights, and all that stuff, and you're getting so abstract. Now, you're talking about cutting taxes, and all these things you're talking about are totally economic things and a byproduct of them is, blacks get hurt worse than whites."

Atwater's point — that you could get whites to vote on the basis of racial resentments without using explicitly racist language — formed the basis of the GOP's "Southern Strategy," first adopted by Richard Nixon. Though you can hear blatant race-baiting just by turning on your favorite conservative radio host (particularly during the Obama presidency), what comes from the man at the top of the ticket has for some time been more subtle. Ronald Reagan may have complained in 1976 about the "strapping young buck" buying steak with his food stamps, and four years later thundered about "welfare queens," but a Republican candidate today wouldn't talk in those terms. In 1988, Atwater masterminded the campaign of George Bush, which made "Willie Horton" a household name, convincing voters that Michael Dukakis was going to send murderous, hypersexualized black men to rape their women and kill their men (though not in so many words, of course). But today no GOP nominee would use that story the way the Bush campaign did, because they know they'd be immediately called out for the clear racism of their appeals.

But here comes Donald Trump, who started his campaign by ranting about how Mexican immigrants are rapists and drug dealers — in his announcement speech, no less. It was clear right then that Trump would say what others would only imply. And in the last week or so he has claimed that in Jersey City, "thousands and thousands of people were cheering" as the World Trade Center fell on 9/11. After a Black Lives Matter protester was punched and kicked at a Trump rally, Trump said "Maybe he should have been roughed up." And he retweeted a graphic with fake statistics about black people supposedly murdering whites, which turns out to have been created by a neo-Nazi.

After innumerable media outlets confirmed that there were no mass celebrations in Jersey City on 9/11, Trump could have said, "I guess you're right — I was probably remembering scenes I saw of people cheering in the West Bank." But he didn't; instead, he insists that he's right and the facts are wrong. But the real point isn't that Trump isn't telling the truth; that has happened many times before and will again. What's important is the thing Trump is trying to communicate with this story.

It isn't an argument about the alleged threat posed by Syrian refugees, or something about ISIS (which didn't exist in 2001). Trump is talking about Americans. He's telling his supporters: Your Muslim friends and neighbors? They're not the assimilated, patriotic Americans they want you to believe. They're not regular people with jobs and families and lives like yours. They're a threat, people to be surveilled and harassed and hated and feared.

Let's be clear about one thing: The rest of the Republican Party's more subtle language on race doesn't excuse their actions. Making it as hard as possible for black people to vote and stirring up racial resentment on the part of whites are still at the core of GOP strategy. But whether out of the goodness of their hearts or simple political calculation, they've agreed that certain kinds of naked bigotry are simply unacceptable in the 21st century.

Donald Trump is not willing to go along with that consensus. So he has adopted a retro racism, telling primary voters in no uncertain terms that if you're looking for the candidate who will indulge and validate your ugliest impulses, Trump is your man. And nearly as shamefully, his opponents tiptoe around the issue, unwilling to criticize him too severely. Even Chris Christie, whose own constituents are the ones being slandered by Trump's 9/11 celebration lie, could only muster that "I do not remember that. And so, it's not something that was part of my recollection. I think if it had happened, I would remember it. But, you know, there could be things I forget, too." The supposedly tough guy from Jersey turns out to be a moral coward of the first order.

The reason isn't hard to discern: Christie and the other candidates don't want to alienate Trump's supporters, who are greater in number than those behind any other Republican candidate. And that could be the most disheartening thing of all: not that there's a candidate willing to make these repugnant appeals, but that so many Republican voters hear them and cheer.