South Carolina, Nevada primaries and Ohio special election: Nancy Mace, Sam Brown win

Mace’s win is also a win for VIEW PAC, one of the GOP women’s groups we're tracking endorsements from in primaries this cycle. One of her several challengers included former state cabinet official Catherine Templeton, who was endorsed by Winning for Women.

We're keeping a close eye on GOP women's group endorsements tonight since, according to our analysis, primary endorsements from groups like Winning for Women, Maggie’s List and VIEW PAC that work to elect more Republican women to office is down this cycle, compared to last. This slow start may be why earlier this month Rep. Elise Stefanik, founder of E-PAC (the Republican counterpart to Democrat’s EMILYs List) told the National Journal’s Hotline that the group plans to work in alignment with the NRCC and party leadership to endorse more women moving forward.

—Meredith Conroy, 538 contributor

It didn't take long for Maine's Austin Theriault to dispatch with his primary tonight. With just 21 percent of the expected vote counted, Theriault leads opponent Michael Soboleski, 67 percent to 33 percent, and the AP projects that Theriault will be the winner in Maine's 2nd District.

—Jacob Rubashkin, Inside Elections

Upstate, the race to replace retiring Rep. Jeff Duncan has essentially fallen into a close three-person race. With 63 percent of the expected votes counted, Trump-endorsed Burns is at 31 percent, Biggs has 30 percent and Jones has 20 percent. Toss in double-digit support for Kevin Bishop, the recently retired communications director for Sen. Lindsey Graham, and it's enough to split the vote in a way that makes it very hard for any candidate to break the majority threshold. Whoever finishes tonight in the top two slots will very likely face off again in a runoff election in two weeks' time. It's been interesting to see the vote regional breakdown as ballots are counted. Jones is leading in Laurens County with 52 percent of the vote there — no surprise, as this is the part of the district that Jones represents in the state House. Burns is leading in Pickens, Abbeville (trivia: this is the first county in the U.S., alphabetically), and McCormick Counties — the first two are slightly more conservative, and the first is his home county.

—Kaleigh Rogers, 538

As we've noted, Mace was one of eight Republicans who voted to oust McCarthy from the speakership last year. Two (Ken Buck and Matt Rosendale) have already resigned or retired from Congress, and McCarthy allies were targeting many of the other six for defeat in primaries this year. Mace was the first of these to face voters, and she obviously survived, so pro-McCarthy forces are 0-for-1.

—Nathaniel Rakich, 538