[The_Media_never_lie]

Much of Mexico is controlled by cartels. The Federal Government does not control the entire country.

[El Cid]

Regarding posts 3 and 4: you could substitute 'Big Pharma Companies' for 'Cartels', and I wouldn't see a big difference between Mexico and the United States. If anything, the 'Big Pharma' companies have more notches on their belts than the cartels.
Our Federal Government does their bidding, as does the Mexico Federal Government the bidding of the cartels.

[Forward the Light Brigade]

Mexican Government exists now only at the behest of the Cartels. I suspect that the US Government is bought off as well and exists (at least the Democratic Party) to serve China and the Cartels. But, this will not last for ever—The Cartels will get to fighting for Control and Mexico will slip into Civil War. The Mexican people will toss the whole lot out and go Maoist Communist and shoot the whole lot.