Freedom is the right to do what you want to do, go where you want to go, and say what you want to say. This could be said to be the basic definition of freedom.
So, what of going where you want to go? If you had complete freedom in this regard, you would be able to visit everyplace in the world.
And, pick the place where you would live.
No immigration rules standing in your way.
This is not necessarily to say that there shouldn't be some restrictions. But, it is to say, if we had total freedom there would be no limits on our movements, and no limits on our immigrating into any land. Even so, there are limits on the other two forms of freedom, freedom to do what you want and freedom to say what you want. We place limits on what you can do, basing the right to restrict that freedom on the principle, "Your right end where my nose begins." And, we place restrictions on what can be said. You are not allowed to libel or slander. You are not allowed to falsely advertise. You are not allowed to threaten someone's life.
So, it is understandable that there will be some restrictions, also, on the right to move about, and the right to choose where you will live. I will suggest, though, that like with the other two categories, limitations on movement should be based on whether harm is caused.
And, I would suggest someone's moving in from south of the border usually does no one harm. A refugee coming from Syria? That does no harm to anyone, either, unless he or she is a terrorist or criminal or threat in some other way. So, let them all in, except for when your vetting unveils the person as a potential criminal or terrorist or such.
If we would be the land of the free, we must freely let people in.