President Trump has called for an overhaul of immigration that replaces a family-based system with a merit-based one. But what counts as merit? We also report on the shooting at a high school in Parkland, Fla., in which at least 17 people died. It was the 18th school shooting in the United States this year. Guests: Caitlin Dickerson, a national immigration reporter for The New York Times; Catherine Porter, Canada bureau chief for The Times. For more information on today’s episode, visit nytimes.com/thedaily.