It was never clear what motivated Rod J. Rosenstein, the deputy attorney general, to hand the investigation of Michael D. Cohen, President Trump’s former lawyer, over to career prosecutors in New York rather than to the special counsel. With that investigation now implicating the president in serious campaign finance violations, we look at how fateful the decision may be. Guests: Neal Katyal, a lawyer who drafted the rules that govern special counsel investigations, and Michael S. Schmidt, who has been covering the special counsel investigation for The New York Times. For more information on today’s episode, visit nytimes.com/thedaily.