In visualizing South Dakota’s weak shift toward Democrats in the midterm election, NBC News did not map the U.S. Senate race, since we had no nominal Democrat on the ballot. Brian Bengs ran as an independent and was incumbent Republican Senator Mike Rounds’s only opponent, so we can’t really line up county results for Bengs/Rounds 2026 alongside Harris/Trump 2024 and determine any shift toward the Democratic brand.
But what would that map look like if we accepted Mike Rounds’s campaign argument that Bengs is just a Democrat in indy clothing? How well did Bengs, who did run as a Democrat for U.S. Senate in 2022, eat into the advantage Rounds got from licking Trump’s immensely popular (in South Dakota) boots?
Statewide, Trump beat Harris in 2024 by 29.18 percentage points. This year, Rounds beat Bengs by 21.00 points. That’s an 8.2 point shift away from Trumpism in the U.S. Senate race, a notably larger shift than the 1.88-point Dem-ward shift Nikki Gronli exerted in the U.S. House race and the 2.18-point blue arrow drew in the gubernatorial race. But it’s still notably smaller than the national 15-point swing from 2024 Trumpism to 2026 sanity.
In addition to quadrupling the average bluish pull exerted by Democrats Gronli and Ahlers, independent Bengs got a big majority of counties—55 out of 66—to give Rounds a lower margin of victory than they gave Trump in 2024:
Now before anyone in a donkey shirt starts dancing for joy, let’s remember what this shift actually produced: Bengs lost by more than 20 points, just like Gronli and Ahlers. Bengs got 64,087 fewer votes than Rounds—better than Gronli’s 85,603-vote deficit and Ahlers’s 82,186, but more votes than were cast in this year’s general election in any one county in South Dakota other than Minnehaha (total turnout there: 75.570).
In 2024, Harris beat Trump in five counties: Buffalo, Clay, Dewey, Oglala Lakota, Todd. Bengs won those same five counties this year… and that’s it. None of the 61 counties that went for Trump in 2024 shifted blue enough to say, “Sure, let’s kick Trump’s pal Rounds out of the Senate!” Bengs only won three counties in 2022—Buffalo, Oglala Lakota, and Todd, so he did improve his personal record (by 67%! Cue the spin-bugles!) but Bengs didn’t do any better than Harris 2024 in convincing counties to pick the good guys/gals over Trump.
And one more small downer: four of the five counties Bengs won—Buffalo, Dewey, Oglala Lakota, and Todd—have red arrows. Their blue margin shrank from 2024 to 2026. Bengs still won them, but by smaller percentage margins than Democrat Harris did two years ago. The historically regular big blue margins in those Dem strongholds make it hard to swing them further blue, but a guy promoting change from the status quo in South Dakota shouldn’t be making those blue margins smaller.
On a similar statistical flip-side note, Bengs’s biggest bites into Trump 2024 margins came in deeply red counties that are neither near nor nearing a liberal revolution. Bengs’s blue arrows exceed 13 points in five counties—Aurora, Butte, Fall River, Harding, and Sanborn—and 14 in one—Perkins. All of those counties but Bengs’s home county of Fall River gave Trump margins over Harris greater than 50 points (Fall River’s margin in 2024 was 49.22) and this year gave Bengs less than 30% of their votes (Fall River only gave their local boy 32.13%).
So even Bengs’s abundant blue arrows don’t point toward victory. They just point toward the same glass ceiling as Gronli’s and Ahlers’s, the 40% that no statewide challenger to one-party rule has managed to break since Democrats Billie Sutton and Randy Seiler eight years ago.