Here's the related op-ed; Why protectionism is a lot like racism;
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?
Related; Landsburg talk at GMU