On the surface, it sounds logical. Mexico has a lot of arable land and a climate that allows double and even triple crop harvests in a year. The big problem, I think, is the sanitary standards such as water supplies polluted with ka-ka and an unwillingness to do what would be necessary to ensure the safety of the food supply such as honest and competent inspection and enforcement.
With transportation being a major cost of agricultural produce, one would think Mexico would have a natural advantage over China. I've worked the import side in Japan and can tell you that their inspectors are both competent and honest to the point that they drive you crazy with their minute attention to detail-- just the opposite of Mexico.
He11 then, lets get our food from japan. Let japan be the middle man.