A Muslim registry: Would it be legal?

Donald Trump threatened a ban on Muslim immigration during his campaign, and, since, his election, incidents of ethnic intimidation are on the rise. That's created a climate of fear among Muslim Americans, who worry about an official Muslim registry. Trump himself has issued conflicting statements, but it's been done before — most recently in the aftermath of September 11. During WWII, Japanese-Americans were interned, and some Trump surrogates have insisted the legal precedent still applies. We update that story.