MOUNT PLEASANT, S.C. — In a strikingly personal last-minute intervention against a lawmaker of his own party, President Donald Trump attacked Rep. Mark Sanford of South Carolina on Tuesday and urged voters to support the woman who is trying to unseat him in the day’s primary.
The president endorsed Katie Arrington, a first-term state legislator, and made a sharp dig at Sanford’s personal life, which included an extramarital affair that infamously took him to South America: “He is better off in Argentina,” the president wrote.
It was not clear how much sway Trump’s tweet would have on primary voters so late in the day. But his endorsement could help spell the end of Sanford’s long career in politics if the contest advances to a runoff.
Trump’s broadside appeared to have been unplanned. Some White House officials were not aware it was coming, pointing out that the president sent the message while he was on Air Force One returning from Singapore. And about 40 minutes after he took aim at Sanford, Trump appeared to confirm he was catching up on news back home.
“Robert De Niro, a very Low IQ individual, has received to many shots in the head by real boxers in movies,” Trump wrote on Twitter, assailing the famed actor who recently used the Tony Awards ceremony to aim a four-letter attack at the president.
The potential for an electoral undoing of Sanford, a former governor in his second stint in Congress, underscores the political headwinds some Republicans are facing this year for exhibiting any measurable defiance of Trump. Arrington has based much of her campaign on criticism of Sanford for his less than total loyalty to the president, and Trump remains a powerful draw for his party’s most dedicated voters.
“There’s a different feel to this race, based on something that I’ve never experienced before, which is at times being hit not on ideas that I’ve espoused or held, but based on allegiance,” Sanford said as he campaigned Tuesday, a few hours before Trump’s tweet jolted the contest in the 1st Congressional District. “I’ve never experienced that before,” he said.
“With some people,” he added, “the allegiance to ideas is secondary to their belief in the importance of their allegiance to a person.”
The threat to Sanford comes a week after Rep. Martha Roby, who represents a deeply conservative district in Alabama, was forced into a July runoff after being tagged as disloyal to Trump.
A defeat of Sanford, either Tuesday or in a runoff with Arrington later in the month, would be especially jarring: He has never lost an election.
His critiques of the president’s behavior, his skepticism of tariffs, and his calls for the release of Trump’s tax returns have irritated many voters in his district, which runs along much of South Carolina’s coast.
Although the district includes Charleston, the state’s largest city, it also takes in rural areas that strongly favor Trump, who carried the district by 14 points in 2016 and has sometimes become a singular litmus test in Republican primaries since then.
“This is certainly, for lack of a better term, a schizophrenic district,” Sanford said Tuesday as he drove his well-worn Chevrolet Suburban to a deli in Summerville.
“The biggest county is Charleston County — it’s a blue county! — so when I do a town-hall meeting, you do 1,000 or 500 people screaming at you saying Trump needs to be impeached,” he continued. “Meanwhile, you find yourself in a Republican primary where you’re not ‘Trump enough.’ It’s like you can’t win these days, in terms of trying to talk about ideas.”
Sanford has been prominent in South Carolina for more than two decades, repeatedly winning elections to Congress and spending two eventful terms in the Governor’s Mansion. But despite that, Arrington has summoned a political strength that surprised many observers in South Carolina.
She has succeeded, in large part, because she swung at Sanford with little apparent reservation or restraint, filling her advertisements and debates with barbs about the congressman’s personal and political integrity.
“You can’t have a seat at the table in the Oval Office, because you have offended the president numerous times,” Arrington told Sanford during a debate on a talk-radio station Monday. “You should have the wherewithal not to go on CNN to bash our president. Instead, work with the president, work with leadership to get done what we want done here.”
Before the primary, Arrington, who has worked in defense contracting, not-so-subtly invoked the marital infidelity that nearly drove Sanford from the governor’s wing of offices in Columbia, the state capital.
“Mark Sanford and the career politicians cheated on us,” she said in one commercial. Referring to the snicker-inducing false alibi of an Appalachian Trail outing that he once offered for an absence from the capital, she said, “Bless his heart, but it’s time for Mark Sanford to take a hike — for real this time.”
The president’s endorsement of Arrington was certainly late in arriving in South Carolina. Trump had already backed, and raised money for, Gov. Henry McMaster, who also faced primary opponents on Tuesday.
Sanford, who could not be reached for comment after Trump’s tweet, said beforehand that he had not solicited support from the White House.
Asked in an interview earlier Monday if he thought Trump would weigh in on the race, Sanford sidestepped the question.
“He’s got a busy plate,” he said. “I respect the fact he’s busy with many other things.”
But Sanford has sensed that he was in political jeopardy, and he partly shed his reputation as a campaign skinflint, pouring close to $400,000 into advertisements for the primary race, including one in which he said, “Overwhelmingly, I’ve voted with the president.” He also relied on a long-cultivated image of accessibility, once again publishing his cellphone number and spending Tuesday driving, without aides in tow, from one restaurant to another to chat up customers and workers.
Most everyone recognized him. It was not clear whether that would be enough.
This article originally appeared in The New York Times.