The cartel was further weakened March 13, when soldiers in Tecate captured Manuel Herrera Barraza, thought to be the gang's primary cocaine and marijuana smuggler between Tijuana, Mexicali, Tecate and southern California. U.S. authorities suspect Herrera smuggled drugs through a 1,000-foot-long tunnel under the U.S.-Mexico border that the Drug Enforcement Agency (DEA) discovered last month.

The decapitation of the cartel's leadership and the following losses have weakened the Tijuana cartel, and other large drug-trafficking organizations will be looking for an opportunity to poach its business. Some could attempt to capture the coveted Baja franchise outright. In either case, the challenges will be quick and bloody.

Four large regional drug organizations are the most likely rivals. Leading the pack is Ismael Zambada's organization, which is based in Culiacan and Mazatlan, in Sinaloa state. Another Sinaloa-based group controlled by Joaquin "El Chapo" Guzman and Hector Luis "El Guero" Palma will also look to steal business in Baja. Osiel Cardenas' powerful Gulf cartel, based in Tamaulipas state, may have ambitions to spread its territory to the West Coast. Standing in the way, however, is the Juarez cartel, which is controlled by the powerful Carrillo Fuentes family.
Among these organizations, Zambada's has the edge. Said to be in his 50s, Zambada is a wily veteran of Mexico's drug underworld who once worked within the Juarez organization.
He now heads an independent but rapidly growing group, and he reportedly still has good ties with the Juarez cartel that may help him to fend off a challenge by the Carrillo Fuentes family.

His organization already is perceived as a threat to the Arellano Felix group. Ramon Felix Arellano was on Zambada's turf when he was killed last month, and U.S. and Mexican authorities now believe he was in Mazatlan to kill Zambada, the Los Angeles Times reported March 20.

In addition to his experience and connections, Zambada holds a geographic advantage. His territory of Sinaloa is across the Gulf of California from Baja California. He can build on his network along the Tijuana-San Diego corridor to forge alliances with current associates of the Tijuana cartel.