Meet the Press NOW — March 23

President Trump walks back his threats to “obliterate” Iran's power plants. New video of the deadly collision at LaGuardia Airport shows the moment of impact between an Air Canada plane and a firetruck which killed two pilots. A former TSA administrator joins Meet the Press NOW to discuss ICE agents being deployed as security lines continue to grow at airports nationwide and President Trump declines to take an off-ramp to end the DHS shutdown.