President Trump at a campaign rally on Wednesday doubled down on his racist remarks about four progressive congresswomen of color, casting them as an existential threat to modern American society and saying "let them leave."

"These left-wing ideologues see our nation as a force of evil," Mr. Trump told his ardent supporters during a campaign rally in North Carolina on Wednesday night. "They want to demolish our constitution, weaken our military (and) eliminate the values that built this magnificent county."

As he took direct aim at Democratic Rep. Ilhan Omar of Minnesota, a defiant Mr. Trump was buoyed by the raucous crowd, which chanted "send her back!"

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The racist chants some in the crowd directed at Omar, a Somali-American and one of two Muslim women in Congress, were reminiscent of Mr. Trump's own factually inaccurate tirade over the weekend against the Minnesota lawmaker and her colleagues Reps. Alexandria Ocasio-Cortez of New York, Ayanna Pressley of Massachusetts and Rashida Tlaib of Michigan.

Mr. Trump on Sunday morning posted a series of tweets deriding "'Progressive' Democrat Congresswomen," alluding to Omar, Pressley, Ocasio-Cortez and Tlaib.

President Trump speaks at a campaign rally at Williams Arena in Greenville, N.C., on Wed., July 17, 2019. AP

"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 (if they even have a functioning government at all), 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," Mr. Trump wrote on Twitter. "Why don't they go back and help fix the totally broken and crime infested places from which they came. Then come back and show us how it is done."

The president claimed that the four Democratic congresswomen "originally came" from foreign countries but only Omar was born outside the U.S. Pressley, an African American, was born in Ohio. Ocasio-Cortez, of Puerto Rican heritage, was born in New York. Tlaib, the daughter of Palestinian immigrants, was born in Detroit. Omar, a naturalized U.S. citizen, was born in Somalia, a country she and her family fled from because of a civil war and ethnic strife.

On Wednesday night, the president again singled out the four progressive lawmakers, accusing Omar of being a fringe legislator who holds anti-Semitic views, denigrates the military and minimizes the 9/11 terrorist attacks. He accused Ocasio-Cortez — who he referred to as "Cortez" because her double-barrelled surname takes "too much time" to say — of stating that Nazis are running detention centers for migrants near the U.S.-Mexico border.

Along with joking that Pressley could be related to rock legend Elvis Presley, Mr. Trump had harsh words about Tlaib, the other Muslim woman serving in Congress. "That's not somebody that loves our country," he said.

Mr. Trump's recent remarks have drawn scathing condemnation from Democrats and some Republicans. Like others in her party who accused the president of stoking racial animus, House Speaker Nancy Pelosi has called his comments "xenophobic" and "racist." On Tuesday, after a bitter partisan brawl, House lawmakers approved a resolution to formally denounce Mr. Trump's recent tirade against four progressive congresswomen of color, with four Republicans joining Democrats to rebuke the president.

The campaign rally in Greenville, North Carolina — one of several rallies Mr. Trump has held this year — also came after a long-shot effort to impeach him failed in the Democratic-led House.

The Trump campaign and Republican National Committee are beefing up staff in North Carolina, which the Trump campaign recognizes is a key state for the president's reelection. The president won North Carolina by less than four points in 2016, and he'll likely face a tougher battle in 2020.

Kathryn Watson contributed to this report.