Look, the worst possible thing for us to do is beat Mexico in a war. Then we'd have to straighten up their affairs, and that always involves a certain additional complement to the immigration quotas to take care of the de riguerre Quislings and collaborators we hire.
Could we at least take control of the Yucatan? That would be a nice part of Mexico to be in U.S. posession. :-)
No, things are quite bad enough now. We are already being invaded. Slowly, and not by force, but invaded still the same. You know the story about the lobster, right? Put him in a pot and turn the heat up slowly and he just stays there and cooks. Throw him in a pot of boiling water and he jumps out.
How about if we just drive them south 20 miles or so, and create a DMZ?