Mark-Viverito Is Elected City Council Speaker Melissa Mark-Viverito Bryan Thomas for The New York Times Melissa Mark-Viverito, a fiery liberal who helped form the City Council's Progressive Caucus, was elected speaker on Wednesday, giving Mayor Bill de Blasio a partner at the controls of the legislative branch who shares his ideology and much of his agenda. Ms. Mark-Viverito, 44, a Puerto Rican-born lawmaker from East Harlem, becomes the first Hispanic to hold what is New York City's second-most-powerful office. The vote was unanimous, 51 to 0. After a bitter fight, in which Mr. de Blasio played an outsized role, Ms. Mark-Viverito's lone challenger, Daniel R. Garodnick of Manhattan, formally conceded on the floor of the Council chamber shortly after 1 p.m., acknowledging the tense battle but saying, "I will do my part to resolve any rifts this process may have caused among us." Until late Tuesday night, supporters of Mr. Garodnick, including the powerful Queens Democratic Party leader, Representative Joseph Crowley, were working furiously to try to sway votes to their side. By Wednesday morning, they had concluded that they did not have the votes needed to win. But it remained unclear until half an hour after the Council meeting was supposed to start whether Mr. Garodnick's supporters would give their votes to Ms. Mark-Viverito or stage a fight. Ms. Mark-Viverito and her bloc of 30 supporters arrived at City Hall en masse at 11:40 a.m. They voiced confidence they had the votes to win but said quietly that they were not sure whether the vote would be unanimous. Mr. Garodnick and his supporters did not arrive until 12:30 p.m. When they did, Mr. Garodnick walked up to Ms. Mark-Viverito and embraced her, to applause from their colleagues. For several minutes, council members from both sides hugged one another. The result of the race represents a victory for Mr. de Blasio, who lobbied council members to vote for Ms. Mark-Viverito, for the Working Families Party, and for several labor unions, particularly 1199 S.E.I.U., the health care workers" union, which put its weight behind Ms. Mark-Viverito as soon as Mr. de Blasio was elected.