(DOVER, Del.) — Democratic Sen. Tom Carper of Delaware announced Monday that he will not seek reelection to a fifth term in the U.S. Senate. Carper’s announcement paves the way for a wide-open contest for the seat he has held since 2001 in heavily-blue Delaware. It also ensures that his unblemished record of never having lost an election during more than four decades in politics remains intact. “If I ran for a fifth term in the Senate and won, it would be a record 15 statewide elections,” Carper, 76, noted in prepared remarks at a Wilmington news conference.