In this new column  in Forbes, the inimitable Steve Landsburg exposes part of the morally repugnant nub of protectionism:
I hold this truth to be self-evident: It is just plain ugly to care more about total strangers in Detroit than about total strangers in Juarez. Of course we care most about the people closest to us-our families more than our friends and our friends more than our acquaintances. But once you start talking about total strangers, they all ought to be on pretty much the same footing. You could say you care more about white strangers than black strangers because you’ve got more in common with whites. Does that make it okay to punish firms for hiring blacks?….
Stealing assets is wrong, and so is stealing the right to earn a living, no matter where the victim was born.
I add only that the other part of this morally repugnant nub is government forcibly restricting domestic citizens’ freedom to spend their incomes as they see fit. (Salt is injected into this wound by the frequent sermons protectionists offer to justify their thuggery.)
I thank Brian Summers for alerting me to Landsburg’s column.