Sean Penn on how Jack Dorsey got him to join Twitter in 2020 and why he's funding COVID testing

Two time Oscar-winning actor and author Sean Penn joins MSNBC’s Ari Melber to discuss his efforts with CORE, the relief organization he co-founded after the 2010 earthquakes in Haiti, to ramp up covid-19 testing in the United States. Penn discusses the $10M donation from Twitter CEO Jack Dorsey and how the tech founder got Penn to join Twitter for the first time in 2020.