The drug cartels have more money than God. They can buy anything they want from the same underworld arms suppliers that supply many gorilla groups. Those fellows are using full auto weapons along with frag grenades. There is no real need for supplies from America.
True. The big cartel bosses are all-powerful. They have warehouses full of money - hundreds of millions - fleets of 747s, yachts, submarines, Lear jets, heavy weapons, anything they want, any time they want it. Human life means utterly nothing to them. Like their recent bus robberies, for example. They'll stop a bus, take the driver's ticket money, then kill him, then kill the 38 passengers on board just for good measure.
Now we have the newest cartel, CJNG (Cartel Jalisco New Generation), currently the most powerful cartel in Mexico, literally murdering their way to the top in less than 5 years, so aggressive and vicious, even giants like Sinaloa and Los Zetas are retreating before them. CJNG soldiers aren't a bunch of scruffy Mexican boys, either; they're full-camo, full-kit, highly trained operators who think nothing of slaughtering an entire village. They're basically unstoppable at this point. No telling where it's all going to end.