He's been known as South Carolina's political comeback kid, but his luck just ran out.

In a startling upset, U.S. Rep. Mark Sanford's re-election hopes were dashed Tuesday when he narrowly lost the GOP primary for South Carolina's 1st District congressional seat to Katie Arrington, a freshman state legislator from Dorchester County.

Before the race was called Tuesday, Sanford conceded, saying he's "always been a realist" and predicted he would lose once the final vote tally was in.

Meanwhile, embattled Archie Parnell won the Democratic nomination for the 5th District, overcoming calls from his party’s leaders for him to abandon his bid after revelations surfaced that he beat his ex-wife in the 1970s.

Arrington's campaign strategy was to align herself with President Donald Trump and harp on Sanford's criticism of the president. She received a last-minute boost from Trump, who endorsed her in a tweet three hours before polls closed.

The loss is a first for Sanford in his political career. He served three terms in Congress before he was elected S.C. governor in 2002. He served two terms as the state's chief executive, and was thought to be vice-presidential material before news broke that he was having an affair with a former television reporter in Argentina and using state resources to visit her.

After his fall from grace, Sanford stunned S.C. political observers by winning a special election for the 1st District in 2013, filling the vacancy left when Tim Scott was appointed to the U.S. Senate.

Meanwhile, Joe Cunningham, a Charleston attorney, won the Democratic primary for the 1st District, advancing to the November election.

In the 2nd District, representing parts of Lexington and Richland counties, Democratic candidates Annabelle Robertson and Sean Carrigan are advancing to a runoff. The two finished first and second, respectively, in a tight race, both failing to exceed 50 percent of the vote needed to win outright.

The winner of that contest will face U.S. Rep. Joe Wilson, R-Springdale, in November.

In a crowded race for the state's 4th District, former S.C. Sen. Lee Bright of Spartanburg appeared headed for a runoff, leading a pack of 13 Republicans vying to succeed U.S. Rep. Trey Gowdy, who did not seek re-election.

Trailing Bright were S.C. Sen. William Timmons, radio host Josh Kimbrell and S.C. Rep. Dan Hamilton of Taylors.

U.S. House of Representatives

1st District

Democratic primary, 287 of 353 precincts reporting

Cunningham: 17,570

Toby Smith: 7,289

GOP primary, 287 of 353 precincts reporting

Arrington: 27,505

Dimitri Cherny: 1,543

Sanford (i): 24,592

2nd District

Democratic primary, 293 of 298 precincts reporting

Phil Black: 5,947

Sean Carrigan: 12,750

Annabelle Robertson: 13,487

3rd District

Democratic primary, 322 of 342 precincts reporting

Hosea Cleveland: 4,868

Mary Geren: 11,738

4th District

Democratic primary, 92 of 231 precincts reporting

Brandon Brown: 2,501

JT Davis: 575

Eric Graben: 2,161

Will Morin: 624

Doris Lee Turner: 2,386

GOP primary, 92 of 231 precincts reporting

(Top four out of 13 candidates)

Lee Bright: 8,190

Dan Hamilton: 3,599

Josh Kimbrell: 3,632

William Timmons: 3,788

5th District

Democratic primary, 361 of 363 precincts reporting

Mark Ali: 3,704

Steve Lough: 2,619

Sidney Moore: 4,753

Archie Parnell: 16,610

7th District

Democratic primary, 226 of 324 precincts reporting

Bruce Fischer: 2,828

Bill Hopkins: 4,636

Mal Hyman: 7,933

Robert Williams: 10,708

GOP primary, 226 of 324 precincts reporting

Larry Guy Hammond: 3,460

Tom Rice (i): 19,761

SOURCE: The Associated Press and SC Election Commission