South Dakota’s at-large congressional district remains a reliably Republican seat in a state with consistent GOP majorities in statewide voting. Incumbent Dusty Johnson’s decision to seek the governorship opened the 2026 contest, but Republican primary voters coalesced around state Attorney General Marty Jackley, who secured roughly 80 percent of the June 2 primary vote after receiving President Trump’s endorsement. Democratic nominee Nicole Gronli and independent Jack Pittman face the general election on November 3 with limited statewide infrastructure or recent polling support. The resulting trader consensus of 93 percent for the Republican nominee reflects the district’s structural partisan tilt and the absence of competitive Democratic performance in recent cycles. Late-cycle developments such as an unforeseen scandal or health event involving the Republican standard-bearer could theoretically narrow the margin, though historical patterns suggest such shifts would be rare.