CULIACAN, MEXICO Two candidates in a local election in the state of Sinaloa, home to Mexico’s most powerful drug cartel, have dropped out of the race after a member of their coalition was shot to death, campaign officials said on Friday. Lucas Lizarraga, campaign coordinator for the coalition ‘‘Together You Win’’, which groups the leftist Democratic Revolution Party and Workers Party with the conservative National Action Party, said the candidates for mayor and state congress in the town of Sinaloa de Leyva are asking to postpone the July 7 vote because authorities are not ensuring their personal safety. They ‘‘have received threats from organised crime groups’’, Mr Lizarraga said.