Donald J. Trump first established his connection with the largely white Republican base more than a decade ago by stoking discomfort with the election of Barack Obama, the nation’s first Black president — the beginning of the so-called birther movement.
In the years since, he has continued to pile up accusations of racism on the campaign trail. This week, Mr. Trump lobbed his latest racially charged attack at former Gov. Nikki Haley of South Carolina, the daughter of Indian immigrants and his closest competitor in the New Hampshire primary, by repeatedly flubbing her given name, Nimarata Nikki Randhawa.
On Friday, Mr. Trump referred to Ms. Haley as “Nimbra” in a post on Truth Social, his social media platform, three days after facing criticism for dubbing her “Nimrada.” Ms. Haley has long gone by her middle name, Nikki.
Both are racist dog whistles, much like his continued focus on Mr. Obama’s middle name, Hussein, and add to a long history of racially incendiary statements from the campaign trail.
Ms. Haley told reporters on Friday that Mr. Trump’s attacks revealed his own insecurities about the presidential contest.
“If he goes and does these temper tantrums, if he’s going and spending millions of dollars on TV, he’s insecure — he knows that something’s wrong,” she said. “I don’t sit there and worry about whether it’s personal or what he means.”
At a rally for Ms. Haley in Manchester on Friday, supporters said they were glad the former governor was countering Mr. Trump’s accusations.
“This is a continuation of the bullying and the third-grade behavior that should have him grounded,” said Kathy Holland, 75, a retired business owner. “We deserve leaders who act grown up.”
Steven Cheung, a Trump campaign spokesman, said that those raising concerns about Mr. Trump’s handling of race were themselves guilty of “faux outrage racism.”
“They should get a life and live in the real world,” Mr. Cheung said.
Mr. Trump’s history with the subject dates back years before his formal entry into politics.
In February 2011, Mr. Trump started pushing the racist lie that Mr. Obama was not a U.S. citizen when he was testing the waters of a potential presidential campaign. Sean Hannity, the Fox News host, discussed the so-called birther issue on almost a nightly basis that April, until Mr. Obama showed reporters his birth certificate later that month.
By then, a CNN poll showed Mr. Trump tied for first in a hypothetical primary. While Mr. Trump opted to return for another season of “The Celebrity Apprentice” as the reality television show’s host instead of running for president, he ran in 2016 on similar themes.
That year, he questioned the citizenship of Senator Ted Cruz of Texas, the first Latino senator from the state, who was born in Canada. Mr. Cruz’s mother is American, which automatically conferred citizenship.
During his failed 2020 re-election bid, he falsely claimed that Kamala Harris, who would become the first woman and first person of color to be elected vice president, did not meet the country’s citizenship requirements.
This month, he returned to that familiar playbook by accusing Ms. Haley on social media of not being a real American eligible for the presidency — even as he was defending his own legal eligibility for the ballot under the Constitution.
“I’ll let the president’s social media post speak for itself,” Jason Miller, a senior Trump campaign adviser, said last week at an event hosted by Bloomberg News.
After the New Hampshire contest on Tuesday, attention in the Republican primary will turn mostly to South Carolina, Ms. Haley’s home state, which has its own history of racially charged politics.
In February 2000, after Senator John McCain won a come-from-behind victory over George W. Bush in the New Hampshire primary, he was the target of a smear campaign in South Carolina. The attacks falsely claimed that Mr. McCain’s wife, Cindy, was a drug addict and that the couple’s daughter Bridget, whom they adopted from Bangladesh, was the product of an illicit union.
“Would you be more likely or less likely to vote for John McCain for president,” some voters were asked in phone calls, “if you knew he had fathered an illegitimate Black child?”
Michael Gold contributed reporting.