Nicolle Wallace monitors the historic SpaceX, NASA launch in real time as it goes from prepared to launch to postponed due to weather concerns. Plus, face masks emerge as a flash point with Trump calling them “politically correct”.

Joined by: MSNBC’s Brian Williams, retired NASA astronauts Peggy Whitson and Clayton Anderson, NBC News correspondents Tom Costello and Kerry Sanders, NBC meteorologist Bill Karins, White House bureau chief for the Washington Post Phil Rucker, associate editor for Real Clear Politics A.B. Stoddard, and senior columnist for Bloomberg Opinion Tim O’Brien