Former Vice President Joe Biden addressed a friendly crowd of union firefighters as he appears on the verge of launching a campaign for the 2020 Democratic presidential nomination. Over the weekend South by Southwest became a major presidential forum. Democrats competed with each other to be the tough-on-tech candidate. This episode: White House correspondent Tamara Keith, Congressional correspondent Scott Detrow, and national political correspondent Mara Liasson. Email the show at nprpolitics@npr.org. Find and support your local public radio station at npr.org/stations.