President Trump this week likened Hispanic immigrants to vermin. He warned that they would “pour into and infest our country.” And he defended his administration’s family separation policy by alleging that parents crossing the southern border with their children were poised to commit crime and murder.

For him, this language is not new.

Echoing the words and images of the white nationalist movement to dehumanize immigrants and inflame racial tensions has become a defining feature of Donald Trump’s presidency and of the Republican Party’s brand.

Trump has stirred supporters at rallies by reading “The Snake,” a parable about a tenderhearted woman who takes in an ailing snake but is later killed when the revived creature bites her. It should be heard as a metaphor for immigration, he says.

The president referred to some African nations as “shithole countries.” He posited that “both sides” were to blame for last summer’s deadly white supremacist rally in Charlottesville. And, again and again, he has accused black football players who took a knee during the playing of the national anthem to protest police discrimination of being un-American.

Among the many ways in which Trump stands out in the lineup of modern American presidents is his aversion to using his bully pulpit to unify the diverse nation he was elected to lead. Rather, he stokes cultural divisions and cultivates tribalism under the banner of his slogan, “Make America Great Again.”

“He takes a blowtorch to the tinder,” said Peter Wehner, a Trump critic who worked in the previous three Republican administrations and is a senior fellow at the Ethics and Public Policy Center.

“For Trump and for his presidency, the culture war is central and defining — and it’s a culture war of a particular kind,” Wehner added. “It’s not the traditional culture war of gay rights and abortion. It’s a culture war that manifests itself in race and ethnicity and nationality. That is his go-to theme.”

Throughout his public life, Trump has pitted one group of Americans against another and inserted himself in racial controversies. In 1989, as a celebrity real estate developer, he took out advertisements in New York’s newspapers calling for the death penalty for five black and Latino teenagers who were wrongfully convicted of raping a white female jogger in Central Park. More recently, Trump perpetuated for five years the lie that Barack Obama was born outside the United States to delegitimize his presidency.

As he leads his party into the potentially perilous midterm election five months from now, Trump is trying to make cultural identity a central theme of the Republican pitch to voters. His messages have been amplified by his surrogates as well as by friendly broadcasters on Fox News Channel and elsewhere in the conservative media.

Trump is calculating that by playing to people’s fears and anxieties he can maximize turnout among hard-core supporters to counterbalance evident enthusiasm on the Democratic side. Fueling Trump’s approach, advisers say, is an unremitting fear of his own: that his base could abandon him if he is deemed too weak on immigration, which was a centerpiece of his 2016 campaign.

Trump’s defenders flatly reject the suggestion that he is intentionally exacerbating the nation’s cultural differences.

“Those who focus on culture and race as the perceived center of POTUS policies are either ignoring or ignorant of the root causes of the problems,” Trump campaign spokeswoman Katrina Pierson said in a text message.

Pierson, one of the few African Americans who work for Trump, said the president’s policies are “centered around law and order and prioritizing American families.” To conclude otherwise, she said, would be exhibiting “bias.”

“I think people are conditioned to see what they want (or are being told) to see in everything that he does, not what he is actually doing,” Pierson said.

Trump has said he recoils from the images, sounds and stories beaming in this week from the border. “I don’t want children taken away from parents,” he said in a speech Tuesday. Yet he otherwise was initially defiant in the face of the growing public outcry, only capitulating Wednesday after the objections had reached a fever pitch. Even then, he suggested to reporters that it was a difficult call to retreat on his policy of separating immigrant children from their parents.

“If you’re really, really pathetically weak, the country’s going to be overrun with millions of people. And if you’re strong, then you don’t have any heart. That’s a tough dilemma,” Trump said. “Perhaps I’d rather be strong. But that’s a tough dilemma.”

Rep. Steve King (R-Iowa), one of the party’s most hard-line voices on immigration, argued that Trump should be focusing more on culture in devising and articulating his policies.

“I don’t hear this president speaking much about race, [but] for me, there are cultural distinctions that matter,” King said. “Whenever you import large numbers of people from singular cultures, you import the culture, too. That’s why a movement towards assimilation in the broader American civilization is so important. That’s been pushed on the back burner and it should be on the front burner.”

GOP congressional leaders are plainly uncomfortable. Some of the most vulnerable House Republicans are running for reelection in swing districts where suburban voters who recoil from divisive rhetoric and policies could prove decisive.

By and large, however, they have not challenged Trump’s approach. Republicans who publicly object risk losing primary elections, being ostracized or mocked by the president. Or they find safe harbor elsewhere, as strategist Steve Schmidt, who helmed George W. Bush and John McCain’s presidential campaigns, did in announcing Wednesday that he was renouncing his membership in the Republican Party.

Before Trump’s retreat Wednesday, his advisers and allies said that the news media are covering the border situation hysterically and that there would not be long-term consequences for the president or the party.

“On a near-daily basis during the campaign, Republican operatives would spend their time freaking out about the controversy of the day,” said Andy Surabian, a former Trump campaign and White House official. “If you listened to them, you would have thought the sky was perpetually falling. The lesson of the campaign is that in Trump’s Washington, things move so fast that no single story will ever define the president, the administration or the party as a whole.”

New polls this week have shown a stark divide over the administration’s family separation policy. A Quinnipiac University poll found that American voters overall oppose the policy, 66 percent to 27 percent, mirroring other surveys.

Quinnipiac found that Republican voters support the separation policy, 55 percent to 35 percent, and that the demographic group with the deepest support is whites without college degrees.

Peter Hart, a Democratic pollster, said that in focus groups he conducted this week in Pittsburgh, many voters expressed “a sense of violation” and that women, in particular, feel empathy for the families being separated.

“This is a very unsettling time for the American voter,” Hart said. “People are unnerved, unsettled and unhappy.”

Whit Ayres, a Republican pollster who has long advocated that his party adopt a more inclusive posture to appeal to the nation’s diversifying electorate, warned that Trump’s strategy is risky.

“In a government of the people, by the people and for the people,” he said, “it helps to have a majority of the people behind what you’re trying to do.”