Originally posted by ordonez1307:
I would have to guess that there is a bigger problem with Mexico than Canada. How strict are the Mexican customs? Maybe the Canadians customs are better?
It isn't just customs. I think it's just the wider economic gap between Mexico vs. Canada. Canada's economy is about the same as the US. Mexico has a lot of poverty. That in turn could create poor customs services, bribes, corruption, etc.
Also, with the geographic location, it's probably easier to smuggle drugs from Central America through Mexico into the US rather than going all the way around to Canada.
Those are just guesses on my part though.