"If you dont think the feds would be protecting the poppy and marajuana fields"

Like they protect the border from the cartels? If the government ends up guarding these "legal" distribution centers this way the conflict will be over pretty quickly.

Yeah...that's just what we need now: corporate "legal" drug mercenaries shooting it out with Zetas commandos and El Chapo Guzman's hitmen across North America. The Government of Mexico threw 50,000 soldiers and tens of thousands of Federal police at the cartels and they have been unable to overpower them. Our theoretical "legal" market would have no idea just what kind of monster it would be up against.

"If it was legal american business could make profits instead."

And then they would become legitimate targets for the drug cartels when they decide to protect their multi-billion dollar business.

I don't really see any evidence that legalizing will work. First of all, drugs make people violent, so violent crime would probably increase. Secondly, if we make everything legal and allow companies like Phillip Morris and Walgreens to provide this poison to anyone who desires it, do you really imagine the leaders of the Zetas and the Sinaloa Cartel sitting down by the side of the road, sulking and saying to themselves "Man...Phillip Morris and Walgreens own this market now...I guess its over for us. We better find some legal work now to make ends meet."

Well, I certainly don't. The cartels would probably start blowing up the distribution centers of the "legal" suppliers and kidnap or assassinate the CEOs and their families. Then they would go after the buyers who chose not to purchase from them, like they do in Mexico today.