WASHINGTON — Racial resentment isn't just a part of President Donald Trump's re-election strategy for 2020. It's the heart of that strategy, and, until this week it was partially obscured by the protective cover of the American flag.

Trump's approach to campaigning and governing has mirrored that of his most successful business enterprise: marketing. He built himself a brand as a politician unafraid of speaking for the dwindling percentage of Americans who are white and native-born and fear, resent or are simply uncomfortable with Muslims, non-European immigrants, and blacks and Latinos born in the United States.

The policy end can be observed in his crusade to gut the Affordable Care Act and cut other federal programs that, on a strict percentage basis, provided more benefits to blacks and Hispanics than whites, a travel restriction that was originally billed as a complete ban on Muslims entering the United States, and a promise to build a wall on the U.S. border with Mexico that has devolved into a humanitarian crisis of overcrowded, squalid detention centers that are likened by some critics to concentration camps.

On a political level, Trump has painted his opponents as un-American and tweeted that four of them should "go back" to what he called their countries of origin. Three of his four targets — Reps. Alexandria Ocasio-Cortez, D-N.Y., Ayanna Pressley, D-Mass., and Rashida Tlaib, D-Mich. — were born in the United States. The fourth, Rep. Ilhan Omar, D-Minn., is a naturalized citizen.

"Send her back!" a crowd at Trump's rally in Greenville, N.C., chanted of Omar as Trump paused for well more than 10 seconds Wednesday night.

The conflation of race and country are essential to understanding how Trump can stoke racial resentment — and then claim that's not what he's doing.

Perhaps accidentally, Sen. Lindsey Graham, R-S.C., clarified that point in defending Trump on Thursday.

"I really do believe that if you're a Somali refugee who likes Trump, he's not going to say 'Go back to Somalia,'" Graham said. "A racist says 'Go back to Somalia' because you're a Somalian or you're a Muslim or whatever, that's just the way he is."

And there's the rub: The racial resentment can be cloaked in the caveat that Trump is pleased with people of color so long as they never disagree with him. If they do, he will paint their dissent — and them — as un-American. And if he's saying their disagreement is about patriotism, then he can argue it's not about their race.

By Thursday, with some Republicans worried that he might hurt their chances of retaking the House, Trump appeared to let up on the gas.

"I was not happy with it," he said of the chant, blaming it on the crowd. "I disagree with it."

But if there's a micro-adjustment to the tactics to appease House Republicans, who run in districts that have different electorates than the full states Trump is trying to win, the strategy seems unlikely to change much.

When he was asked whether it bothered him that his remarks were being portrayed as racist, Trump said he didn't care because of their power to draw voters to him.

“It doesn’t concern me because many people agree with me,” he said at the White House on Monday. “A lot of people love it, by the way.”

His re-election strategy is born both of choice and of necessity. Trump has made no sustained effort since he won the presidency to reach out to parts of the electorate who found him unpalatable in 2016. With little hope of attracting large numbers of those voters to his side in 2020, he is left with only one path to re-election.

It's the one that fits his branding: find and turn out to the polls as many whites with high degrees of racial resentment as possible while disparaging Democrats enough to depress turnout for their eventual nominee. It worked for him in 2016, and Trump is a creature of habit.

Whether he can pull that off again at a time when even his allies are questioning the degree to which he is campaigning on unabashedly racist themes remains to be seen.

"I don't think the president is a racist," former White House Communications Director Anthony Scaramucci said in a BBC interview this week. "But here's the thing, if you continue to say and act in that manner, then we all have to look at him and say, 'OK, well, maybe you weren't a racist, but now you're turning into one.'"

Trump has often said he is "the least racist" person.

His counternarrative on policy is that black, Hispanic and Asian unemployment levels are at record lows — a function of the overall economic expansion that began under President Barack Obama and has continued under Trump.

Still, it is no mistake that, in the midst of a presidential election, Trump has targeted four congresswomen of color — and Omar, specifically — rather than any of the candidates who are actually trying to beat him. While Omar represents fewer than 800,000 people in the Minneapolis area, and Trump represents 330 million or so, she embodies what his most ardent supporters fear the most.

A refugee from war-ravaged Somalia, she has dark skin and wears a hijab in accordance with her Muslim beliefs. Now 37, she came to the United States as a child, was granted asylum and became a citizen in 2000, winning election to the House in 2018. She literally came to this country as a teenager and took one of the most powerful jobs in America — albeit from an African American Muslim, former Rep. Keith Ellison, D-Minn., who was elected to statewide office.

Omar is also an unabashed progressive and a harsh critic of Trump's agenda, of American military interventionism in places like Somalia — she has blamed the United States for its part in the 1993 Battle of Mogadishu in which 18 American service members and hundreds of Somalis were killed — and of both Israel's treatment of Palestinians and the role of pro-Israel donors in American politics.

Trump has spent much of the past week trying to tie the rest of the Democratic Party to her political positions. It was when Omar and her three allies split from their caucus over a border policy vote that Trump tweeted they should "go back." That was over-the-top enough that four House Republicans voted with all of the chamber's Democrats to condemn him for racist commentary in a high-profile but entirely symbolic statement.

But most Republicans who have criticized Trump's attacks on the four lawmakers have been careful to make sure that they are at least equally as harsh in their denunciations of the congresswomen.

Doug Heye, a Republican strategist who spoke out against the chant at Wednesday's rally on Twitter and received blowback from the left for not going far enough, said Republican officials are in a double bind when it comes to leveling criticism against Trump, because most of their constituents want them to support the president and it's almost impossible for them to say anything harsh enough to satisfy his opponents.

He said Trump and his Democratic rivals are playing dangerous political games.

"I think Trump is very specifically picking at scabs that bring up racial resentment, there’s no question about that," Heye said. "At the same time, these are extremely prominent members of Congress who are picking at some of those same scabs."

Specifically, he noted that Omar introduced an Israel-boycott measure in the House just after the chamber voted down an effort to impeach the president Thursday — a move that was sure to spark more controversy surrounding her and keep her in the news.

Former Florida Rep. David Jolly, who served as a Republican but has since left the party, reacted emotionally to Graham's remarks about race, country and Trump's attacks on Omar in an MSNBC interview.

"What Lindsey Graham did there, trying to quiet her, is disgusting," he said.

The question is how many voters may be feeling the same way about Trump's re-election strategy.