In the early 20th century the American South was ravaged by pellagra,

a nasty disease that produced the “four Ds” — dermatitis, diarrhea, dementia and death. At first, pellagra’s nature was uncertain, but by 1915 Dr. Joseph Goldberger, a Hungarian immigrant employed by the federal government, had conclusively shown that it was caused by nutritional deficiencies associated with poverty, and especially with a corn-based diet.

However, for decades many Southern citizens and politicians refused to accept this diagnosis, declaring either that the epidemic was a fiction created by Northerners to insult the South or that the nutritional theory was an attack on Southern culture. And deaths from pellagra continued to climb.

Sound familiar?

The moral of this story is that America’s uniquely poor response to the coronavirus isn’t just the result of bad leadership at the top —

although tens of thousands of lives would have been saved if we had a president who would deal with problems instead of trying to wish them away.

Trump supporters mostly ignored the guidelines for coronavirus safety at the rally in Tulsa, Okla., on Saturday.Credit…Christopher Lee for The New York Times

We’re also doing badly because, as the example of pellagra shows, there’s a longstanding anti-science, anti-expertise streak in American culture — the same streak that makes us uniquely unwilling to accept the reality of evolution or acknowledge the threat of climate change.

We aren’t a nation of know-nothings; many, probably most Americans are willing to listen to experts and act responsibly.

But there’s a belligerent faction within our society that refuses to acknowledge inconvenient or uncomfortable facts, preferring to believe that experts are somehow conspiring against them.