The point of this was post was to illustrate that neither ethnic homogeneity nor a lack of natural resources qualify as unsurpassable barriers to the creation of redistributive welfare states. It has nothing to do with immigration except insofar as immigration contributes to ethnic heterogeneity. If I wanted to illustrate that immigration also does not qualify as an unsurpassable barrier (which it doesn’t), I would make a post actually addressing that point.
Now see, Prof. Stone, was posting that in response instead really so hard?