Douglas Todd: Progressives must wrestle with dilemma on migration

It’s called the “progressive’s dilemma,” a term popularized by two Canadian scholars of multiculturalism. It describes the way people with left-of-centre views often find themselves in a fix on the issue of migration.
They become ensnared by a 21st-century debate over whether a higher immigration rate weakens domestic support for social-welfare programs. Most scholars conclude it generally does: The main questions they’re now trying to answer are to what extent and