“Extremism, racism, nativism, and isolationism, driven by fear of the unknown, tend to spike in periods of economic and social stress—a period like our own. Americans today have little trust in government; household incomes lag behind our usual middle-class expectations. The fires of fear in America have long found oxygen when broad, seemingly threatening change is afoot. Now, in the second decade of the new century, in the presidency of Donald Trump, the alienated are being mobilized afresh by changing demography, by broadening conceptions of identity, and by an economy that prizes Information Age brains over manufacturing brawn. “We are determined to take our country back,” David Duke, a former grand wizard of the Ku Klux Klan, said in Charlottesville. “We are going to fulfill the promises of Donald Trump. That’s what we believed in, that’s why we voted for Donald Trump. Because he said he’s going to take our country back. And that’s what we gotta do.”