Take a look, for instance, at what happened with those 1980 refugees — mostly those fleeing war’s aftermath in Southeast Asia. There are now about 2 million Vietnamese Americans in the U.S., and in 2015 they boasted higher median incomes and educational attainment than most other Americans. That’s to say nothing of other refugees who over three centuries have helped to make America a font of global popular culture, the birthplace of atomic energy and a pioneer of the digital economy.