WASHINGTON — President Trump said on Sunday that a group of four minority congresswomen feuding with Speaker Nancy Pelosi should “go back” to the countries they came from rather than “loudly and viciously telling the people of the United States” how to run the government.

Wrapped inside that insult, which was widely established as a racist trope, was a factually inaccurate claim: Only one of the lawmakers was born outside the country.

Even though Mr. Trump has repeatedly refused to back down from stoking racial divisions, his willingness to deploy a lowest-rung slur — one commonly and crudely used to single out the perceived foreignness of nonwhite, non-Christian people — was largely regarded as beyond the pale.

[Update: Four congresswomen denounce Trump after he says they hate America.]

“So interesting to see ‘Progressive’ Democrat Congresswomen, who originally came from countries whose governments are a complete and total catastrophe, the worst, most corrupt and inept anywhere in the world,” Mr. Trump wrote on Twitter, “now loudly and viciously telling the people of the United States, the greatest and most powerful Nation on earth, how our government is to be run.”