Christina Bohannan won the Democrat primary in Iowa's 1st Congressional District on Tuesday, CBS News projects, giving her a third chance at trying to unseat Republican Rep. Mariannette Miller-Meeks. 

Bohannan, a University of Iowa law professor and former state representative, beat political newcomer and healthcare worker Travis Terrell to advance to the November general election. 

The Iowa district, which spans the southeastern corner of the state, has a history of close races, with Miller-Meeks defeating her Democratic opponents by slim margins. 

The nonpartisan Cook Political Report has rated the race a toss up, and House Democrats' campaign arm, the Democratic Congressional Campaign Committee, sees it as one of its top targets to flip in the November elections. 

Miller-Meeks has served in Congress since 2021 after winning her 2020 election by six votes, in what was one of the closest House races in U.S. history. 

Miller-Meeks won by a much wider margin — about 20,000 votes — in 2022 when she faced Bohannan for the first time. But her lead narrowed considerably during their 2024 rematch, when Miller-Meeks won her third term in Congress by less than 800 votes — one of the narrowest margins that year. 

The results of the 2020 and 2024 races weren't finalized until weeks after the election after the close margins led to recounts. 

Miller-Meeks and Bohannan have similar amounts of cash on hand, according to the latest Federal Election Commission data. 

Republicans in Iowa control all four House seats, both Senate seats and the governor's mansion. Democrats in Iowa also invested heavily in the governor's race and the Senate seat, which will be open since Sen. Joni Ernst announced her retirement. Democrats are hoping that the national environment — including high gas prices, the war in Iran and fallout from the tariffs — will help them break up the GOP's dominance.