Macomb County’s growing Black population could play a critical role in deciding who wins one of the most closely watched congressional races in the country, political observers say. By just a half percentage point in 2022, Republican John James narrowly defeated Democrat Carl Marlinga for an open congressional seat that covers Macomb County and neighboring Rochester and Rochester Hills in Oakland County. Marlinga, a former county prosecutor, judge, and U.S. attorney, is running for the seat again, and part of his campaign’s strategy is focused on appealing to the sizable Black population in the 10th Congressional District.