MICHAEL BARONE: Immigration reformers should learn from history.

There’s an obvious lesson here for immigration policy. Immigration can promote social mobility, but not always. The United States got high-skilled immigrants in the Ellis Island period largely by happenstance. Today Canada and Australia profit from upward mobility because their immigration laws admit only those with high skills.

I think Barone's wrong on this one. The U.S. used to be an upwardly mobile society because immigrants were encouraged, almost required, to be productive. That is no longer the case.