GREENVILLE, N.C. — President Trump waited for 13 seconds, as the chants from the crowd of thousands grew louder.
“Send her home!” the North Carolina audience yelled, mimicking Mr. Trump’s recent tweet attacking a Somali-born Democratic congresswoman.
“Treason!” one man screamed.
“Traitor!” shouted another.
The moment Wednesday night, a microcosm of the angry tribalism that often emanates from Mr. Trump’s campaign rallies, immediately caused ripple effects for the president and his party. Some Republican members of Congress denounced the chant as racist and xenophobic. Mr. Trump tepidly disavowed his supporters’ words, only to praise them the following day. For Democrats, especially the candidates seeking to defeat Mr. Trump, the impact of the rally was clear: This will be a general election focused on race, identity and Mr. Trump’s brand of white grievance politics.
Until this past week, the 2020 field has generally tried to ignore the president’s incendiary language — talking about it, the thinking goes, only gives him more power. Instead, candidates have preferred to discuss policies, making the case for themselves by advocating changes in the criminal justice system or maternal health, or ways to eliminate the racial wealth gap.
Now some feel an urgency to take a different approach.
“This election will be a referendum, not on Donald Trump, but a referendum on who we are and who we must be to each other,” Senator Cory Booker of New Jersey said. “But this is going to get worse before it gets better.”
Senator Kamala Harris of California, the most viable woman of color to run for president, said that the scenes from Mr. Trump’s rally, while personally upsetting, were not surprising.
“When we’re on that stage together in the general, I know he’ll try to pull the same thing with me,” Ms. Harris said. “But I’m fully prepared for that. I’m up for it. Because he is small. He is wrong. He is a bully.”
And at a fund-raiser in Los Angeles on Friday, former Vice President Joseph R. Biden Jr. told supporters that Mr. Trump is “tearing at the social fabric of this country.”
“This is not hyperbole,” Mr. Biden said. “The fact of the matter is this president is more George Wallace than George Washington.”
But even as Democratic candidates universally denounced Mr. Trump’s comments, they did not agree on how the eventual presidential nominee should combat the racial division embedded in those words. Do you, on the campaign trail, talk directly about the president’s inflammatory language, racism and discrimination in this country? Or do you talk about jobs and the economy?
Democratic Party leaders, particularly establishment figures with ties to Barack Obama’s and Hillary Clinton’s presidential campaigns, have largely followed a strategy of careful avoidance: responding to the president’s most inflammatory moments, while attempting to redirect the political debate to what is often described as “kitchen table” issues, such as health care and wages.
However, an increasingly vocal group of Democratic grass-roots organizers and pollsters believe that Mr. Trump’s words and legislative actions amount to a cohesive playbook of white identity politics, meant to court white voters of all economic tiers around the idea that their fates are linked, and are under threat by an increasingly diversifying America. They argue that racism and the public performance of it is a “kitchen table” issue for many voters — black and white — that must be dealt with head-on.
“Just as much time and resources as the nominee spends on targeting and messaging around health care and wages and climate change, they should spend an equal amount of resources around an alternative racial vision for the country,” said Cornell Belcher, a prominent pollster who worked with Mr. Obama. “This isn’t a goddamn distraction.”
Ana Maria Archila, the co-executive director of the progressive group Center for Popular Democracy, said Democrats must embrace this moment as an opportunity.
“You have to be able to speak powerfully about our willingness to belong together,” Ms. Archila said. “Don’t just condemn the racism and the language but use it as an opportunity to argue for a vision of the country in which we can all be included.”
To some progressives, the stakes are not just winning in 2020. The fate of American identity could be at risk. Ms. Archila pointed to several policy actions taken by the administration, including the push for a citizenship question on the census, as proof that the “Send her back!” chants were indicative of a permanent ideology among Republicans that was bigger than Mr. Trump.
Mr. Booker, whose campaign has struggled to break out of the crowded Democratic field, said he believed that the country was in the midst of a “moral moment.” He compared Mr. Trump to a famous demagogue of America’s past: Theophilus “Bull” Connor, the commissioner of public safety in Birmingham, Ala., who used violent tactics to uphold segregation and oppose the civil rights movement in the 1960s.
“They didn’t beat Bull Connor by bringing bigger dogs and bigger fire hoses,” Mr. Booker said. “It was activism that inspired people from all different backgrounds.”
During the 2016 election, Mrs. Clinton made repeated arguments that Mr. Trump spoke in divisive and inflammatory ways, and her slogan of “Stronger Together” was meant to invoke a vision of racially diverse America at odds with Mr. Trump’s nativism.
Ms. Harris said she felt Democrats were better positioned to combat Mr. Trump’s language in 2020 because voters now know he did not deliver on his populist promises. He has “a rap sheet now,” Ms. Harris said. “Maybe before someone said, ‘Oh, it appears he’d run a good business,’ and there was this aura surrounding him. But now he’s been exposed for who he really is.”
Valerie Jarrett, the former senior adviser to Mr. Obama, said any Democratic nominee would do well to mimic the former president’s messaging. She said her advice to the Democratic field would be to focus on crafting a clear policy message in the primary but to spend the general election attempting to motivate the party’s base, who experienced a dip in energy in 2016. Ms. Jarrett warned candidates not to let Mr. Trump’s combative tone move them away from the sort of strategy that Mr. Obama used to win.
“The country has not changed since his re-election,” Ms. Jarrett said. “Voters are looking for someone who can unify and show us that whoever the president should be a role model for our children.”
But whether such a strategy can still work in a political universe reshaped by Mr. Trump’s Twitter feed remains an open question.
Mr. Biden is betting it can. He remains the leading Democrat in national polling and has pointed to Mr. Trump’s reaction to the white nationalist rally in Charlottesville, Va., in 2017 as a primary factor in his decision to run for president.
“There’s always in every society an underbelly that has racist and xenophobic tendencies; thank God it’s a minority,” he told the crowd at the Los Angeles fund-raiser. “From the day Trump ran, he’s been trying to appeal to that underbelly.”
In the past five years, polling has shown a consistent shift among Democrats, especially among white Democrats, on issues of race and identity. According to analysis from Data for Progress, the progressive think tank, 2016 was the first time a majority of white Democrats agreed that discrimination held back black people. In 2014, 41 percent of Democrats agreed that racial discrimination was the main reason black people could not get ahead. That number increased to 64 percent in 2017, according to Pew Research.
On the campaign trail, Democrats have been noticeably more vocal in discussing race with primary voters, particularly concepts of structural racism, institutional discrimination and white privilege.
Last weekend, former Representative Beto O’Rourke of Texas wrote a lengthy explanation to his supporters after learning that he and his wife were both descended from slave owners. Mr. O’Rourke supports reparations for slave descendants and has spoken repeatedly about his own privilege as a white man. During a visit to South Carolina last month, he visited the Gullah-Geechee Nation, descendants of slaves brought from West Africa.
Senator Elizabeth Warren of Massachusetts makes a point to mention low black homeownership rates in her stump speech, and the reaction is often stronger among white audiences in Iowa than black ones in South Carolina. During an event in Youngstown, Ohio, this month a white woman asked Senator Kirsten Gillibrand of New York to explain white privilege, prompting a lengthy response that garnered more than 1.4 million views online.
“Institutional racism is real,” she said. “It doesn’t take away your pain or suffering, it’s just a different issue.”
But talking about institutional racism to a crowd of primary voters is different from talking about it in a matchup against Mr. Trump.
Ryan Enos, a political scientist at Harvard University who has studied voters’ attitudes toward race, said that to the extent the president’s racial divisiveness is a political strategy, it could be an effective one.
“There are a lot of people who are uncomfortable with someone who covers her hair in Congress,” Mr. Enos said, referring to Representative Ilhan Omar of Minnesota. “It is really an ethical and electoral issue, and if it works, that earns Trump another four years in the White House.”
Mr. Belcher, the pollster, was also skeptical of his party’s ability to meet Mr. Trump on his playing field.
“White progressives don’t understand race in this country and conservatives and Republicans do,” he said. “But they better learn, because Donald Trump is coming.”
Asked why he was pessimistic, Mr. Belcher laughed.
“Because I’m black,” he said.