What Immigration Restrictionists Can’t Foresee

Periodically, a journalist or policy maker informs us that Americans are panicked about immigration, and suggests that the United States should engineer the demographics of its population through immigration policy. Writing in The Atlantic, for example, David Frum argues that the U.S. should slash legal-immigration levels and restrict family reunification in favor of selecting immigrants based on skills, moves he believes would have positive economic and social consequences.

But in the past, when the government has tried to control demographics with immigration policy, it hasn’t gotten what it wished for.

Consider the country’s response to the wave of immigration in the early 20th century, to which Frum compares our current wave, and which represents