The November battle for control of the House is coming into focus in Tuesday’s primaries, as Republicans pick nominees to challenge Democratic incumbents in Ohio and Indiana.

GOP voters nominated former state Rep. Derek Merrin, setting up a rematch with Democratic Rep. Marcy Kaptur in Ohio’s 9th District — on paper, a district that looks like one of the GOP's best chances to flip a Democratic-held seat this year.

For years, Republicans have unsuccessfully tried to knock off Kaptur in the Republican-leaning seat. And they were able to make her district even redder as part of a redistricting compromise last year. But candidates have repeatedly stumbled against Kaptur, who has shown resilience on the campaign trail throughout a long career.

Merrin defeated several rivals for the Republican nomination, including state Rep. Josh Williams and Madison Sheahan, the former No. 2 official at U.S. Immigration and Customs Enforcement.

Democrats need to net just three seats to retake control of the House — and a number of GOP districts look vulnerable. Any opportunity for Republicans to go on offense and defeat a Democratic incumbent would be critical to their chances of holding on to the majority.

Republicans also scored an early win last year with that redistricting compromise, which shifted Ohio's 1st District to one Donald Trump carried by 3 points in 2024. On Tuesday, Republicans anointed Trump-backed Eric Conroy, an Air Force veteran who also worked at the CIA, as their nominee to run against Rep. Greg Landsman in the Cincinnati area.

While Republicans improved their odds in two seats in the redistricting compromise, the Akron-area 13th District held by Democratic Rep. Emilia Sykes moved to the left during redistricting: Then-Vice President Kamala Harris carried it by about 3 points in 2024. Carey Coleman, a former longtime local media talk show host, is the projected Republican primary winner there.

And in Indiana, where Trump's play to unseat Republican state senators has captured most of the attention, there's one House district that could be competitive this fall. Republican Porter County Commission member Barb Regnitz is projected to win her party’s nod to take on Democratic Rep. Frank Mrvan. Harris only won this seat by less than 1 percentage point in 2024 — but Mrvan has repeatedly won re-election despite the competitive nature of his district.

While many House incumbents cruised to victory, a handful had closer-than-expected races.

Freshman Rep. Jefferson Shreve of Indiana defeated his Republican primary opponent, Sarah Brown, by just a few percentage points. Brown, a homeschool advocate and author, raised just $22,000 for her bid through the middle of April, while Shreve, who was endorsed by Trump, raised about $350,000 and pitched in $2 million of his own money to his campaign.

GOP Rep. Jim Baird of Indiana had Trump’s endorsement, but he faced a spirited challenge from state Rep. Craig Haggard. There had been a flurry of outside spending in the final weeks here from both sides, but Baird was projected the winner.

And Rep. Victoria Spartz also won her Republican primary in Indiana, too. But both Baird and Spartz were hovering around 60% of the vote Tuesday evening, a low mark in a primary for a sitting member. And while Baird ran against a notable opponent, Spartz's challenger, Scott King, was a relative unknown.