Ramesh Ponnuru is right that Santorum is overselling the argument in favor of (a certain kind of) immigration restriction. Low-skill immigration is not bringing down the wages of native born workers around the median income. Depending on the study, low-skill immigration brings down the wages of lowest-skill native born and/or lowest-skill foreign-born workers.

That is still very important because our lowest-skill workers are having lots of trouble with their unemployment rate, their labor force participation, and their family stability. An immigration policy that drives down the wages of our lowest-skill workers is wrong. Those workers and their families matter regardless of whether they are labeled “middle-class”. While I like Marco Rubio (and Santorum for that matter), there is nothing crazier in our politics than Rubio simultaneously supporting wage subsidies for low-income workers (something I support too), and immigration policies that increase future low-skill immigration.

Restricting future low-skill immigration is not going to increase the incomes of middle-class Americans. Restricting future low-skill immigration can be part (but only part) of a strategy for making the American economy work better for a troubled segment of America’s labor market and society.