My friend Sumit mentioned some problems with open borders unrelated to economic issues. He raises good points; there are significant challenges associated with assimilating immigrants. Will they learn English? Will they overwhelm native culture? Will they believe in the essentials of America’s Constitutional republic?

I suspect that immigrants are still a net win, but I agree with Sumit that 100m new Americans could have negative effects. In any case, the core point of my previous post remains: the pseudo-economic arguments against immigration are bogus. And even if we don’t open the borders, it is clear to me that the US can and should welcome many more immigrants—both skilled and unskilled—to the land of opportunity.