How Are the Mexican Drug Cartels Fighting Marijuana Legalization?

In November California voters will decide whether to legalize marijuana (Prop 19). I've wondered for some time how the Mexican cartels who stand to lose in a huge way will fight this; after all, you can't directly give money to an American politician who will then stand in front of cameras and say "We should keep marijuana illegal so international drug-and-gun runners can stay in business."

The California Beer and Beverage Distributors group is getting press recently for their vigorous opposition to marijuana legalization. While they do have their own reasons for opposing legalization, I wonder what we'd find if we followed the money very closely.