Coca needs specific environmental conditions not readily available in most of the U.S. I know people who have grown coca indoors just for the fun of it - they had humidity problems on the one hand and mold on the other - the percentage of cocaine in the leaves varies but it is never very much, I don't know if you need a ton of leaves to make a lb of blow but consider that if the leaf is one percent cocaine (kinda high if I remember) it would take 100 lbs, one tenth of a percent would take 1000 lbs. Chewing the stuff is pretty fun and long long ago we used to buy "decocanated" coca leaves in health food stores before they finaly figured out that nothing was ever done to the leaves at all. A box cost about 5 bucks and made enough wonderful tea for two of us to last most of the day. As has been said, the flow of cocaine will not much be affected by searching individuals - the bulk of it comes over or under the border in huge quantities. This means that even if the cartels forfeit a load, more is being shipped in parallel. You can afford to lose three or four times as much as makes it through and still make a hell of a lot of money.