Hahahaha! Presidente Fox loves the illegal immigration. Money sent back home to Mexico provides the second largest national source of income. And in addition to losing all that income, if they stayed home they might cause trouble for the Mexican government which has always been near-legendary for corruption.
There's no way Fox will actually work toward stemming it; the effort will have to be uninilateral from our side, and Fox has gripped mightily about the current border patrols.
If I where president I would promise Vicente Fox that if illegal immigration didn't stop he would end up in a spider hole, and I always keep my promises.