Why does the US allow itself to be invaded? Common criminals anyone? I support immigration whole heartedly, but it must be done legally. Those who want to flout the legal system must be punished - in this case severely
Good luck. With the way things are in Mexico right now, and other select countries, the promise of a better life in America, it would be hard to discourage the immigrants from crossing over. Even if we sent them to jail, for some of these people, living in an American jail would bring in more food and roofs over their heads than what they had in their old country.
There are only two main ways, off-hand I can think of, that would discourage immigration. Either we go the Doomsday route, and build a giant wall with 20mm autocannons that kills every heat based living object that approaches to within 500 yards or so of the wall, or we improve the living conditions in Mexico to where people will no longer want to migrate to America.
Personally I would be in favour of annexing, or merging with Mexico.