I hear a lot of stupid, stupid comparisons between America and the Roman Empire so why not just make Mexico a province? 
Actually, I always thought that would be a good idea.
Not a probable idea, but a good one.
It should've been done 150 years ago, though, to make it work better.
I know I sound like someone from the 19th century, but is it not the destiny of America to be the city on the hill, the light to enlighten the ignorant?
I know, I know.....fantasies.