Drug gangs and graft conspire to turn one Mexican state into a violent and dominant force in the drugs trade A lethal combination of corruption and criminal gangs fighting for control of a booming heroin trade has turned one two-lane road in Mexico’s Guerrero state into what many call “the corridor of death.” The road links Chilpancingo, the Pacific Coast state’s capital, to heroin-producing mountains nearby, where rival gangs are vying for a bigger share of the lucrative heroin market in the U.S. Nearly 1,200 people were killed in the state this year through June after 2,200 died last year. Officials say nearly all were linked to organized crime. The bloodshed largely occurred in poor neighborhoods of the Acapulco and Ixtapa-Zihuatanejo beach resorts and in communities like Chilapa, a town…