At least in terms of the short- and medium-term, I agree with Robert VerBruggen on the practical question that he emphasizes: Both a large and sustained reduction in illegal immigration and a reorientation of legal immigration toward skills should be a higher priority than reducing legal immigration levels. He is right, I think, that the odds of success for a political effort to reduce legal immigration would be worse.
VerBruggen was commenting on an essay by David Frum that urges a reduction in legal immigration. If we instead followed a course of deterring illegal immigration more effectively than we do today, moving toward a skills-based legal immigration system, and refraining from expanding legal immigration very much — and I take this combination of policies to be what VerBruggen is recommending — then we would drive down both total immigration levels and low-skilled immigration levels. We would, then, go a significant distance toward achieving what Frum wants.
On one point, though, I am inclined to side with Frum rather than VerBruggen. It is true, as the latter notes, that in general voters have become more inclined to say that immigration levels should rise and less inclined to say that they should fall. But it can be simultaneously true that public opinion has turned more favorable toward high immigration and that high immigration has generated a mass backlash with significant political effects — and I think it was true in 2016.
Frum believes that we should have a more moderate intake of immigrants over the last generation, that President Trump is a dangerous demagogue, and that these two points are connected: that is, that a policy of lower immigration would have made Trump’s election less likely. But most of the people who share Frum’s alarm about Trump are liberals, and do not seem inclined to listen to him on immigration.