The rationale for the Torah’s dietary code is found here: "You shall be holy for Me, for I the Lord am holy; and I have separated you from the peoples to be Mine" (Lev. 20:26). The main purpose of the kosher laws is to remind us to make distinctions between classes—of animals and of nations. This doesn’t mean there’s anything unwholesome about a horse (non-kosher) as compared with a cow (kosher), but rather that we must always bear in mind that God created peoples and animals separate, with their differences, for reasons of His own. The colors of the rainbow create a beautiful visual array. When the same colors are mixed together haphazardly, on the other hand, their beauty is marred and muddied. Just so, God destroyed the Tower of Babel [Gen. 11:1ff.], that famous experiment in world government, and scrambled the languages of mankind, creating a "babble" of tongues, specifically to head off any future efforts to merge nations haphazardly. True, in Mosaic law, there is such a thing as a convert, a ger, typified by the Biblical Ruth [Ruth 1:16ff]. A convert becomes, in almost every practical respect, like any other Israelite: "For the congregation—the same decree shall be for you and for the proselyte who sojourns, an eternal decree for your generation; like you like the proselyte shall it be before the Lord. One teaching and one judgment shall be for you and for the proselyte who sojourns among you" (Num. 15:15-16). Notice the key point about "one teaching and one judgment." It is possible to change nationalities, but highly demanding, just as conversion to Judaism is in Jewish law down to modern times. Any attempt to translate Biblical values into American policy prescriptions will go seriously astray if it is for the sake of throwing open American citizenship to all comers without imposing serious, challenging, and difficult preconditions.
- David Klinghoffer, Borders & the Bible: It’s not the gospel according to Hillary, May 16, 2006, at http://article.nationalreview.com/?q=MWU0Y2Y0ZWNkZmE2OWI1Mzg4YmI1ZmMzY2QzMzA5ZTA=