Mayoral candidate Alvin Brown (right) picked up a key endorsement Friday from a fellow Democrat who operates on a national scale. U.S. Sen. Bill Nelson (middle) publicly endorsed Brown’s run for mayor during a news conference along the Southbank Riverwalk. Nelson said Brown is prepared to become the next Jacksonville mayor because of his ability to build consensus and accomplish goals, which will be important for economic-development projects such as deepening the St. Johns River channel to assist the port. Brown’s ability to unite will be needed, said Nelson, to “face the gargantuan problems we face in the future.” Nelson, the senior Florida senator, said he has known Brown since the candidate was an intern in his office. Brown said he was honored by the endorsement from someone who gave him an opportunity. U.S. Rep. Corrine Brown (left) and Duval County School Board member Betty Burney also endorsed Brown.