Jerry Bowyer offers a biblical lesson:
The biblical case against abortion is inferential. The Bible doesn't speak directly to the topic. It lays out some principles -- sacredness of life, humanity of the unborn -- that lead to the conclusion that abortion is not permitted. It's the same with stem cells, child tax credits, faith-based social service provisions, etc.As they say in these parts, "Well, maybe it is and maybe it ain't."
Immigration is different: The Bible is explicit. In the Torah, Moses commanded, "Do not mistreat an alien or oppress him, for you were aliens in Egypt." The Bible is unabashedly pro-immigrant.
The same Torah commanded the Israelites, when they entered the promised land, "But of the cities of these people, which the LORD your God gives you for an inheritance, you shall leave nothing alive that breathes. You shall utterly destroy them - Hittites, Amorites, Canaanites, Perizzites, Hivites, and Jebusites - as the LORD your God has commanded you."
Does that command give us permission to, in the words of Mr. Taggart, "slaughter every last Indian in the West"? How about if our army takes Matamoros, should we put every Mexican there to the sword? Of course not. Why not? Because the command is not given to us as a nation, just as Bowyer's command is not given to us as a nation. As soon as someone tries to create American political policy based on what God told the Israelites, the klaxon ought to go off in your head. Danger, Will Robinson: there is a world of difference between how the individual ought to act and how a nation ought to act, especially when that nation is not chosen of God for a specific purpose precisely as we're not.
There is a lot of truth to what Bowyer is saying on a personal level. We as Christians, if we are to love our neighbor as ourselves, must include those who are strangers and pilgrims among us in that love; we have no right to pass them by on the Samaritan road and leave them bleeding simply because they don't belong here. They are our neighbor, they are created in the image of God, and we owe them the same love we owe our fellow countrymen, individually.
But there is another issue than the personal, and that is the political. Paul said in Acts that God "has made of one blood all nations of men to dwell on all the face of the earth, and has determined the times before appointed, and the bounds of their habitation." There is a separation of peoples for a reason (it goes back to Babel) and there are nations and national boundaries for a reason (think of it as the American "separation of powers" but on an international level).
So what is the "biblical" policy regarding whether a non-Israelite nation should allow foreigners to enter or to become citizens? The truth is that there isn't one. While Christians have a duty to love their neighbor, they have no duty to make their government let more neighbors in. Such is completely the province of government, to be organized for the purposes of the government. Nations, like individuals, will answer to God, but they will answer for different things.
To say the Bible is pro-immigrant (person) is not to say that it is pro-immigration (policy). Mandated national policies are few and far between in the Bible, and we ought to be very careful about trying to construct them from commands that God gave someone else.