Are Immigrants the Secret to America’s Economic Success?

When we accuse a politician of dehumanizing some ethnic group, we’re usually being metaphorical. The other day, however, Donald Trump said it straight out: Some migrants are “not people, in my opinion.”

Well, in my opinion, they are people. I’d still say that even if the migrant crime wave Trump and his allies harp on were real, and not a figment of their imagination (violent crime has in fact been plummeting in many cities). And I’d say it even if there weren’t growing evidence that immigration is helping the U.S....