Representative Mike Bishop, a Republican whose district stretches westward from suburban Detroit, is up against an energized Democratic base that has donated heavily to the campaign of Elissa Slotkin, a first-time candidate and former Defense Department official. Read more

Mr. Bishop has generally voted in line with President Trump. Ms. Slotkin has focused her campaign on health care issues. The district leans Republican, with a mix of affluent suburbs, rural farmland and more liberal-leaning areas around Lansing and East Lansing.