In 1862, California physician Arthur B. Stout published a scathing report with a terrifying title: “Chinese Immigration and the Physiological Causes of the Decay of the Nation.” According to Stout, newcomers from China were spreading tuberculosis, syphilis and other diseases that could “insidiously poison the well-springs of life” and “corrode the vitals of our strength and prosperity” in the United States.

Sound familiar? That’s what Republican politicians have been saying in recent weeks about the coronavirus: It’s being brought here by immigrants. That’s not true, any more than it was about the Chinese and disease in the 19th century. But it speaks to an old theme in American history: When an epidemic arrives, we blame non-Americans.

That happened right after the coronavirus pandemic began, of course, when President Donald Trump called it the “China virus” or even “Kung Flu,” a racist trope that helped fuel a dangerous increase in anti-Asian violence.

And it’s happening again now, despite there being no evidence to suggest that Latin American immigrants are responsible for recent upticks in coronavirus infections, as Florida Gov. Ron DeSantis (R) and others have suggested, while deflecting criticisms about their policies banning masks or slowing vaccinations. Evidence suggests that recently arrived migrants have similar infection rates as the local population in places such as McAllen, Tex., and more importantly, nearly 100 percent of migrants released into the United States have tested negative, or have been offered or provided a place to quarantine if they test positive.

But Americans have always linked epidemics to those deemed outsiders, as Alan M. Kraut demonstrated in his indispensable 1994 book “Silent Travelers.” They provide a convenient scapegoat, absolving the rest of us from responsibility for the disease and death in our midst.

So when a smallpox epidemic seized San Francisco in 1876, the city health officer blamed it on “unscrupulous, lying, and treacherous Chinamen who have disregarded our sanitary laws.” Others charged that Chinese immigrants were spreading leprosy, one of the most fearsome diseases of all. To drum up support for restricting Chinese immigration, which would culminate in the federal 1882 Chinese Exclusion Act, White San Franciscans drove disfigured “Chinese lepers” around the city — although there was no evidence that these men actually had leprosy.