Businessman, perennial candidate, and provocateur Paul Nehlen tried to ride Donald Trump’s coattails into Congress only to lose the Republican primary by 70 points. He continues to descend to new lows.

This holiday season has found Nehlen dreaming of a white Christmas, dabbling in alt-right tropes and boasting about reading an author once described as the “Marx of the anti-Semites.” What began as a dog whistle now blares like a trumpet.

“Nehlen is dead to us,” responded an adviser to Steve Bannon, who like many on the populist Right was a former supporter. The late Phyllis Schlafly, a more seasoned conservative operator, was also among those who endorsed Nehlen over House Speaker Paul Ryan, R-Wis., in 2016.

Bannon’s detractors don’t take this disavowal seriously, but weeding out the “fringe element” he dismissed as “losers” and a “collection of clowns” on his way out the door of the White House is more important to the future of an enlightened American nationalism than any West Wing turf war with Ivanka Trump. It is both a moral imperative and a political necessity.

Populist conservatism has already proven uniquely vulnerable to grifters and candidates who have no business running for office. It is also susceptible to the allure of any argument that can be described as politically incorrect no matter how noxious, dumb or ugly, making the kind of self-policing essential for successful movements difficult. It is easier to adopt a “No enemies to the Right” stance.

Barry Goldwater’s famous line might need to be updated for the Breitbart era: “Extremism in the defense of liberty is no vice; moderation in the pursuit of justice is virtue-signaling.”

Trump, by far the most successful politician to run on a Bannonite platform, has himself vacillated between what CBS News’ Will Rahn has called “rainbow nationalism” — “one that puts all Americans first regardless of religion or color or any of the other ways we identify as smaller groups, and emphasizes the quality of life of people living here over any abstract or international concern” — and more racially polarizing rhetoric.

What hope then is there for far less media-savvy candidates running as post-Tea Party insurgents to do better?

There are two recent precedents, one on each end of the political spectrum, that could be instructive. The first is how Richard Nixon and Ronald Reagan addressed the legitimate concerns of millions of Americans who cast their ballots for the segregationist George Wallace, who won nearly 10 million votes as a third-party presidential candidate in 1968. The two Republicans’ opponents still accused them of practicing a racist “Southern Strategy,” despite winning re-election in 49-state landslides while carrying states like New York and California. But they tackled crime and welfare, among other core issues, without appropriating the genuine racism inherent in Wallace’s platform.

Another example is how Cold War liberals rebuffed communists and the hard Left at a time when it was by no means risk-free to do so. Their political opponents still red-baited them. McCarthyism was a real phenomenon. So, however, was communism and mainstream liberals recognized there were actual subversives trying to infiltrate their political efforts. Instead of denying or embracing them, they rejected them. The resultant coalition governed America until liberalism succumbed to other temptations in the 1960s.

Similarly, the ubiquity of charges of racism against conservatives makes denial or acquiescence in the face of the real thing no more justifiable morally or productive politically.

Peter Beinart tells the story of liberal anticommunism in the George W. Bush-era book The Good Fight. I don’t agree with most of the post-Cold War foreign-policy advice contained therein (neither, at this point, does Beinart) but it is not a bad read for those in search of tactics for a conservative antiracism. The subtitle, after all, calls on liberals to “Make America Great Again.”

Nehlen is a far less consequential political figure than George Wallace, Henry Wallace or for that matter former Ku Klux Klan leader David Duke in his early 1990s prime. He is unlikely to ever be elected to anything. But he is an important warning sign for those who want a revivified civic nationalism and greater solidarity against global elites to become bigger parts of American conservatism. There are people who, for fun or profit, would like to redirect this populist energy into narrower, less defensible concerns.

Let them have their hashtags and lash out on Twitter with no obvious support in the real political world.