Not to hijack a thread, but seeing as I am a libertarian I might be able to help out here.

Like most things in life there are trade offs, and sometimes the only way one thing will work is with the complete removal of something else. Open borders can work and IMHO would be a great solution. However, the only way they work is if you have zero social programs/assistance. With social programs like welfare and such, the dregs of society will move to the place where they get the most "free" shit, so an open border with those programs is the death of the nation, just as it is killing Europe now.

However, remove those government programs, remove welfare, food stamps, and the like and you remove any reason for the dregs to move anywhere. The people that will be taking advantage of the open borders will be those that have a true vested interest in being somewhere and knowing they will have to support themselves once there.

If both programs and open borders are there, the whole thing will collapse, so I get your point. Just trying to add a bit of discussion.