If his basic points in today’s post are that America has an interest in Mexico’s success and that its success would make our immigration problems much lighter, then he is obviously correct. (Note, however, that this point is already a departure from the open-borders orthodoxy. If mass immigration were really as terrific as it claims, the reduced flow of immigrants would be a regrettably byproduct of Mexican prosperity.) But promoting development in Mexico is a very long-term project, and success is, to put it mildly, not assured. If continuous mass immigration from Mexico is a problem, then shouldn’t we assert some control over our borders in the interim?