New at e3ne.org, I discuss my conversations with high school students about the moral legitimacy of border restrictions:
We started our discussion with a little bit of improv theatre. I played a foreigner trying to get into the United States without documentation. Students volunteered to play a border guard trying to keep me out. Between us lay an invisible line, the border. I engaged them in a conversation about the moral justification of keeping me out.
To my surprise, the students were more confidently pro-immigration than I was! I played devil’s advocate some and tried to get them to appreciate the nuances of immigration policy.
My view is that borders are morally illegitimate because the state is morally illegitimate. Nevertheless, it can be permissible to use force to stop someone from settling in a particular area when doing so is necessary to safeguard public order or to preserve the minimal conditions for effective political autonomy for the existing communities in that area. For instance, I think it would be permissible for the U.S. government or an American state to prevent a large group of totalitarians from settling on their territory, provided the law does not provide a means for preventing them and their immediate descendants from obtaining citizenship. In a similar way, it would be appropriate for the Israeli government to prevent radical Arab nationalists from settling in their territory en masse. It’s also appropriate to exclude violent criminals, suspected terrorists, invading foreign armies, and, in the context of a welfare state, those unable or unwilling to work.
PILEUS 
Why not just open the borders but with the stipulation that no one immigrating would ever be eligible for any kind of state-provided welfare benefits? Or voting.
Some (currently most) immigrants will contribute to the fisc through taxes, so I would see it as unjust to disqualify them from taking out roughly in proportion to what they put in. But if you appear to be a pure scrounger, you may be excluded. Prohibiting from voting works if you can deny citizenship while permitting permanent residency. Yet that is difficult to do in the U.S. under current law, and I worry about what the next generation of, say, a crop of totalitarians would do with their automatic citizenship.
Would you close the borders if you believed that the State IS morally legitimate?
Probably not, but I would evaluate immigration policy in light of the welfare of Americans alone rather than the rights of everyone. That form of analysis lends itself to a more restrictionist position, although it’s possible that something pretty close to open borders still wins out, for the same reason that open borders to trade and capital flows make sense.
The easiest way to stop someone from settling is to not let them in in the first place. We allow persons from Mexico in; if they arrive through designated entry points and show that they don’t intend to become residents. But arguing that the state is morally illegitimate because it doesn’t have a “valid” contract with its residents is not an argument for non-residents with no contract whatsoever to come through willy-nilly, take what they value and leave a mess to clean up.
What do immigrants take? What mess do they leave? Does immigration across national borders violate others’ rights in a way that immigration across town, state, or ecozone borders does not?
Yes, foreign-national immigrants violate rights in ways that internal immigration does not. It all has to do with culture. You cannot maintain a civilization like that of the West unless you have a forceful majority who say “this is the way it’s going to be,” and make it stick. In America, that means compliance with law, observing the limitations of government and individual freedoms in the Constitution, self-reliance, private property, capitalism, etc. When massive numbers of people come in from other cultures that do not share those values—and have no intention of adopting them—you’re going to have Balkanization. And that way lies madness…along with death and destruction on a massive scale. Ann Coulter is quite correct and quite courageous in explaining it in her book “Adios America.”
How does changing culture violate rights, apart from the en masse settlement of those with authoritarian or totalitarian ideologies? And the latter isn’t what’s happening in the U.S. today.
It doesn’t take a mass immigration of people with authoritarian or totalitarian ideologies in order to destroy an existing culture. All it takes is the refusal or failure to support the existing one. In the case of America, if a large scale replacement of the existing supporters of the American culture results in the end of honest transparent elections, if bribes are regularly expected and accepted by government functionaries, if there’s no commitment to or support for the values reflected in the Declaration of Independence and the U.S. Constitution… then American culture as it exists will die and be replaced by something else. Whatever replaces it depends upon the cultural habits and values of the incoming population.
I just don’t see those outcomes as particularly likely with 2 or even 3 times the level of current immigration.