DETROIT (AP) — In a congressional career that has spanned nearly a half-century, John Conyers is no stranger to fending off re-election challenges. However, they usually come in the fall, not the summer.

While the Michigan Democrat who ranks second in seniority in the U.S. House remains a heavy favorite for a 25th term, his path back to Washington could be a little bumpier this time. He faces a reconfigured district that even has a different number, and that uncertainty has drawn four challengers for the Aug. 7 primary — two of whom have raised enough money to at least get their messages out.