[[ Anyone who advocates this should be anathema to true conservatism. ]]
In an earlier time, that _was_ conservatism.
Not only was it conservatism, it was the official policy of The United States. Thus, we once had immigration laws that actually made sense, by permitting some to come in (those who were seen as best being able to preserve and propogate the ethnic character of the U.S.A as it then was), and specifically excluded others. Discriminatory? Yes, of course. Unfair? Yes, again, of course.
All that changed in 1965, with Ted Kennedy's immigation reform. How's that working out for us?
The "conservatism" we have today has been fundamentally changed from what is was up until the 1940's. Once, conservatism endeavoured to "keep things as they were"; now, it's become a mushy feelgood philosophy. To be a "modern conservative" seems to mean that one should embrace a set of tenets as fanciful in their own ways, as the leftist's ideology is to him. Reality need not intrude.
Whether such changes are for the better or for worse, is your decision.