My two cents on immigration issues

It only takes a look at the street signs here in California, or in Arizona, Tejas or Florida, or to think of the state names themselves to be reminded that much of the US was Mexico, and that before that Spaniards or British came to this continent there were the natives whose extermination in no way validates the sovereignty assumed by the occupiers. The fictional borders drawn by whoever killed more of their opponents have little validity other than the current practical purposes of a social contract that could take into account the benefits of discouraging xenophobia and discrimination and allowing the possibility of greater cooperation, harmony and peaceful relations between the not-so-different people's of this world.
If massive immigration into certain countries of the world is a problem, the solution lies not in fencing off entire territories, but in exposing and uprooting the rapacious economic policies that are perpetuating and deepening the impoverishment of third world nations, countries often rich in natural resources for too long manipulated and exploited by the superpowers.