In South Carolina’s Republican gubernatorial primary, Lieutenant Governor Pamela Evette secured a notable endorsement from former President Donald Trump but fell short of an outright victory in the initial round held Tuesday. With nearly two weeks to go before the runoff on June 23, Ms. Evette will face State Attorney General Alan Wilson, who positioned his campaign around affordability and infrastructure amid the state’s rapid growth.

The June 23 runoff pits a Trump-backed candidate against an entrenched state official in a state that has consistently favored Republican governors since 2002 and supported Mr. Trump in three consecutive presidential elections. The outcome will serve as another measure of the former president’s continuing influence within the Republican Party, which has varied in other recent races nationwide.

Preliminary results showed Ms. Evette leading narrowly with just under 30% of the vote, while Mr. Wilson trailed at approximately 26%. Several other prominent Republicans, including U.S. Representatives Nancy Mace and Ralph Norman, did not advance, along with business outsider Rom Reddy. Ms. Mace publicly endorsed Mr. Wilson for the runoff, emphasizing the need for a "law-and-order governor" and signaling a unification among candidates following a sometimes contentious primary.

Ms. Evette, an Ohio-born businesswoman who has served as lieutenant governor alongside Governor Henry McMaster since 2019, has sought to position herself as his natural successor. The term-limited McMaster has endorsed her, and Mr. Trump suggested she consider the governor’s son, Henry McMaster Jr., as her running mate—an idea that drew criticism and allegations of a backroom deal, which Ms. Evette denied. Henry McMaster Jr. later withdrew his name from consideration.

Mr. Wilson, a veteran of the National Guard, has also demonstrated loyalty to Mr. Trump, though he has emphasized to voters that an endorsement alone will not secure victory. His campaign features a “Trump Tough” section on its website, and he regularly praised the former president during the campaign trail.

Both candidates have made their appeals to the party’s base, but voter concerns seemed to center around practical issues affecting South Carolina, such as managing population growth, infrastructure challenges, and rising costs of living. At Ms. Evette’s watch party, she drew enthusiastic responses for her commitment to improving the state’s roads.

The primary campaign saw moments of acrimony, including between Ms. Mace and Mr. Wilson, but these divisions appeared to soften with her endorsement. Ms. Mace, who has publicly spoken out about her experience as a trauma survivor and was involved in efforts to release files related to Jeffrey Epstein, suggested that her stance on those issues may have cost her key political support, including from Mr. Trump.

The winner of the upcoming runoff will face Democrat Jermaine Johnson, a state representative who secured his party’s nomination on Tuesday. South Carolina Republicans will look to the runoff not only as a choice for state leadership but also as an indicator of Mr. Trump’s ongoing sway in the party ahead of the 2024 elections.