I can't believe I'm saying this buy: maybe building a wall could help with the drug cartel thing.
Border security is an important issue and everyone has a vested interest in keeping dangerous criminals out of the United States (for instance, drug smugglers). However, walls don't work very well. For one, most of these cartels are extremely adept at building tunnels, and unless we're actually on board with the idea of spending an absolutely absurd amount of money covering every inch of the border with a wall, then smugglers will just enter through the unprotected portions anyway.
Regardless of which option we choose, drug smuggling will still be pretty much impossible to eliminate. My typical liberal solution is to suggest increasing access to addiction services in order to cut down on the overall demand for drugs in the US (coupled with legalizing the production and distribution of some of the safer ones like weed), but that's very idealistic.
In summary, building a wall would be ridiculously expensive and wouldn't significantly cut down on the overall amount of drug smuggling. Annoying Orange's idea to 'make Mexico pay for the wall' isn't even possible anyway. There's no way for us to pressure them into actually funding the construction, unless you're willing to consider cutting off some of our trade agreements with Mexico. Ironically, that would probably re-open the markets for Mexican crops and would reduce the number of campesinos fleeing to the US for better pay. No wall needed.