South Dakota Attorney General Marty Jackley (R) has won the state's at-large House seat, according to Decision Desk HQ, defeating Democrat Nikki Gronli in the race to succeed outgoing Rep. Dusty Johnson (R).
Jackley, who has served two terms as the state's top prosecutor, will replace Johnson, who decided not to seek a fifth term and instead ran for governor. The projection came early Tuesday night, with Jackley leading by a wide margin.
With more than 99% of the vote still uncounted, Decision Desk HQ projected Jackley would win by roughly 34 percentage points. The victory ensures the seat remains in Republican hands, a status it has held since 2011. South Dakota last sent a Democrat to the House in 2010, when then-Rep. Stephanie Herseth Sandlin lost her reelection bid to Kristi Noem.
The state has been a reliable Republican stronghold in the Trump era. Donald Trump carried South Dakota by nearly 30 points in 2024, and Johnson won his last race by a 44-point margin over Democrat Sheryl Johnson.
Jackley entered the general election as the clear favorite, with the nonpartisan Cook Political Report rating the race as “solid Republican.” He secured the GOP nomination in June, easily defeating James Bialota with over 79% of the vote. His path to the nomination was further smoothed when state Sen. Casey Crabtree dropped out in February and endorsed him.
Jackley's career has been rooted in law enforcement. He served as U.S. attorney for South Dakota from 2006 to 2009 before being appointed state attorney general, a role he held until 2019. He returned to the office in 2023 after winning the Republican nomination at the party's state convention the previous year. He also made an unsuccessful bid for governor in 2018, losing the GOP primary to Noem.
His opponent, Gronli, had previously served as South Dakota's state director of rural development for the Department of Agriculture. She secured the Democratic nomination without a primary challenge after other candidates withdrew.
Throughout his campaign, Jackley highlighted his experience as attorney general, emphasizing his record on criminal prosecution and presenting himself as a conservative focused on public safety and law enforcement, including fighting drug trafficking and supporting border security. His victory adds to a string of Republican wins in the region, echoing similar outcomes in other races like Michigan's 11th District and Illinois' 9th District.
