They're doing this because they want to create an EU-style zone for our part of the globe. There's nothing more to it than that.
I disagree. The Hispanic vote moves towards those who enable hispanic immigration. Be it legal or illegal.
I do find it funny that where people used to be called "tinfoil hatters" for mentioning your second point they are now called "commies" or "protectionists". Cant deny something when people can see it happening I guess. I will probably be hated for this but I would probably support more open borders in the hemisphere if permanent residency and new citizenship in the US were radically reduced. Since just the opposite will be true they lose my support.