President Trump is threatening to place tariffs on Mexico to try to stop the flow of migrants across the border, but Congressional Republicans question how that will help stop the influx. Plus, Congress puts big tech companies on notice. This episode: White House correspondent Tamara Keith, Congressional reporter Kelsey Snell, national political correspondent Mara Liasson, White House correspondent Franco Ordoñez, and political reporter Danielle Kurtzleben. Email the show at nprpolitics@npr.org. Find and support your local public radio station at npr.org/stations.