The disturbing re-emergence of 19th-century pseudoscience

The second half of the 19th century left a lot of junk in America's mental attic: that place we let old notions, impressions and delusions pile up rather than taking them to slumber in a faraway landfill. Lurking between the lines of the America First caucus' white-centered nostalgia is a pernicious gesture of historical erasure, implying that Americans from more recent nonwhite immigrant generations put the essentials of a common culture at "unnecessary risk," while the people whose great grandparents were watched with horror and disgust by "Anglo-Saxon Americans" in the 19th century are now, safely, us. This stuff gets dusted off and buffed into comfortable euphemism in the America First manifesto, invoking history as evidence that "social trust and political unity are threatened" by immigrants "imported en masse into a country," who will also need the support of an "expansive welfare state" to "bail them out should they fail." The America First caucus figured descendants of the huddled masses, the restless refuse and the tempest tossed wouldn't see themselves, and their family's stories, in the new Americans finding their feet. It's been over 50 years since the Immigration and Nationality Act of 1965 opened the US to Africans, Asians and Latin Americans "yearning to breathe free."