INDIANAPOLIS (AP) — In Tuesday’s election, Republicans are hoping to take a northwestern Indiana congressional seat that has been a Democratic stronghold since the 1930s in the GOP-dominated state.

National Republicans targeted first-term Democratic Rep. Frank Mrvan for defeat as part of their push toward regaining a majority in the closely divided U.S. House, throwing their support behind Jennifer-Ruth Green, a Black U.S. Air Force veteran.

Democrats have typically won the 1st District, which hugs Indiana’s Lake Michigan shoreline near Chicago, by large margins, but former President Donald Trump closed the gap by appealing to working class voters in the district that has some of the country’s largest steel mills.

Mrvan easily won election in 2020 over a perennial Republican candidate with the endorsement of retiring 18-term Democratic Rep. Pete Visclosky and strong labor union support. Mrvan faced a tougher time this year as outside political groups linked to both parties each poured millions of dollars into TV ads in the district.

Green, who would become the GOP’s only Black female House member if she wins, touted herself as a Trump supporter during the Republican primary campaign but has backed away from talking about him in recent months. Utah’s Mia Love became the first Black Republican woman in Congress with her 2014 victory. She lost her reelection bid in 2018.

The 1st District is the only one of Indiana’s nine congressional districts that appears to have the potential to change political hands this election, although two new House members will be elected.

Republican former state Sen. Erin Houchin is heavily favored in southern Indiana’s 9th Congressional District to replace GOP Rep. Trey Hollingsworth, who unexpectedly announced in January he wouldn’t seek reelection after three terms.

Voters in northern Indiana’s solidly Republican 2nd District will decide a successor to GOP Rep. Jackie Walorski, who was killed along with two staff members in an August highway crash.

Rudy Yakym, an executive with Elkhart logistics company Kem Krest who was endorsed by Walorski’s husband, won a vote among Republican precinct committee members to replace Walorski on the ballot. If Yakym wins as expected over Democrat Paul Steury, a high school science teacher from Goshen, and Libertarian William Henry, he could be sworn into office in the coming days to complete Walorski’s term through the rest of this year and then start a full two-year term in January.