Rich Lowry: What’s Happening in Sweden

As if on cue, riots broke out in a heavily immigrant suburb of Stockholm as soon as the media mocked President Donald Trump for a vague warning about immigration-related problems in Sweden.

At a campaign rally, Trump issued forth with a mystifyingly ominous statement. "You look," he declared, "at what's happening last night in Sweden." What? Had the president invented a nonexistent terror attack? As it turned out, the reference was to a segment on Sweden he had watched on Fox News the previous night rather than to any specific event in the Nordic country.

The ensuing discussion quickly took on...