Adam Hochschild reviews two books on the Ku Klux Klan.

Most of us who grow up in the United States learn a reassuring narrative of ever-expanding tolerance. Yes, the country’s birth was tainted with the original sin of slavery, but Lincoln freed the slaves, the Supreme Court desegregated schools, and we finally elected a black president. The Founding Fathers may have all been men, but in their wisdom they created a constitution that would later allow women to gain the vote. And now the legal definition of marriage has broadened to include gays and lesbians. We are, it appears, an increasingly inclusive nation.

Some of us are, and others of us prefer Trumpworld.

But a parallel, much darker river runs through American history. The Know Nothing Party of the 1850s viciously attacked Catholics and immigrants. Eugenics enthusiasts of the early twentieth century warned about the nation’s gene pool being polluted by ex-slaves, the feeble minded, and newcomers of inferior races. In the 1930s, 16 million Americans regularly listened to the anti-Semitic radio rants of Father Charles E. Coughlin.

And then there’s the Klan, introduced so lovingly in Gone With the Wind, and Birth of a Nation before it.

All along, of course, even while sticking to rhetoric of tolerance and inclusion, politicians have made winks and nods toward that dark river of which the Klan is a part. Richard Nixon had his Southern Strategy. Running for president in 1980, Ronald Reagan sent an unmistakable message by giving a speech about states’ rights near Philadelphia, Mississippi. George H.W. Bush used the notorious Willie Horton campaign commercial. And now suddenly, it’s no longer just winks and nods. Only when pressed by a reporter did Donald Trump in early 2016 reluctantly disavow the support of Klan leader David Duke. “David Duke endorsed me? O.K., all right. I disavow, O.K.?”

Ya satisfied? Goddam libbruls.

In all three of its historical incarnations, the KKK had many allies, not all of whom wanted to dress up in pointed hoods and hold ceremonies at night. But such public actions always have an echo. “The Klan did not invent bigotry,” Linda Gordon writes, “…[but] making its open expression acceptable has significant additional impact.” Those burning crosses legitimated the expression of hatred, and exactly the same can be said of presidential tweets today.

She ends her book by writing, “The Klannish spirit—fearful, angry, gullible to sensationalist falsehoods, in thrall to demagogic leaders and abusive language, hostile to science and intellectuals, committed to the dream that everyone can be a success in business if they only try—lives on.” One intriguing episode links the Klan of ninety years ago to us now. On Memorial Day 1927, a march of some one thousand Klansmen through the Jamaica neighborhood of Queens, New York, turned into a brawl with the police. Several people wearing Klan hoods, either marching in the parade or sympathizers cheering from the sidelines, were charged with disorderly conduct, and one with “refusing to disperse.” Although the charge against the latter was later dropped, his name was mentioned in several newspaper accounts of the fracas. Beneath the hood was Fred Trump, the father of Donald.