MOUNT PLEASANT, S.C. — Mark Sanford smiled. He shook hands, posed for photographs and drove himself around his district on Election Day. He ordered a chocolate milkshake.
But all day, after all these years as a governor and a congressman, he seemed to know what might be coming: his first concession speech. So it came to be in a crowded restaurant here on Tuesday night, hours after he had been openly mocked by President Trump, then knocked aside by a rival who vowed a close alliance with the White House. Mr. Sanford, a politician first sent to Washington as an insurgent of one era, was toppled in a different moment by a different kind of renegade.
“We are to cower before the people who elected us, and I get their verdict tonight,” Mr. Sanford said, reading from scribbled notes on a legal pad, as it became clear he would lose his House race against Katie Arrington in South Carolina’s Republican primary.
Even for a politician accustomed to humiliations — his marital infidelity and ill-fated, infamous trip to the Appalachian Trail, which was actually Argentina, still proved ripe for jabs this campaign — Mr. Sanford’s political unraveling in South Carolina was a striking comedown that somehow seemed both impossible and inescapable.
“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,” Mr. Sanford said earlier in the day as he campaigned. “I’ve never experienced that before.”
“With some people,” he added, “the allegiance to ideas is secondary to their belief in the importance of their allegiance to a person.”
When a reporter asked him whether he was optimistic about his chances, he replied, “I think confident is too strong a word.”
And that was before Mr. Trump’s late-afternoon tweet, posted from Air Force One less than three hours before the polls were to close here. Mr. Trump complained that Mr. Sanford was “nothing but trouble” and “very unhelpful” in advancing his administration’s agenda. He endorsed Ms. Arrington, but also included a pointed dig at Mr. Sanford’s personal life. “He is better off in Argentina,” the president wrote.
It is not clear how many voters saw the president’s 11th-hour endorsement and how many of them it swayed. But Mr. Trump’s tweet in support of Ms. Arrington’s bid in the First Congressional District was perhaps the final death knell in a two-act political career that toggled between spectacles and subtle moments.
Mr. Sanford, after all, was a governor who once brought squealing pigs into the South Carolina State House to make a point about pork-barrel spending. His penchant for sleeping in his congressional…