DOVER, DE (AP) – Democrat U.S. Sen. Tom Carper of Delaware says he will not seek reelection to a fifth term. Carper announced he will retire when his current term expires in 2024. His announcement paves the way for a wide-open contest for the seat he has held since 2001. He is the fourth Democrat senator to announce plans to retire in this coming cycle. Carper served five terms in the U.S. House and two terms as governor before being elected to the U.S. Senate in 2000.