During the primary, Delaney was endorsed by former President Bill Clinton, U.S. Congresswoman Donna Edwards, Comptroller Peter Franchot, the "Washington Post", and the "Gazette". On April 3, 2012, Delaney won the five-candidate Democratic primary field with 54% of the vote. The next closest opponent, State Senator Robert J. Garagiola, received 29% of the vote, 25 points behind Delaney.