Tonight on The Last Word: Stocks tumble as Donald Trump attacks Federal Reserve Chair Jerome Powell. Also, Harvard University sues the Trump administration over funding cut threats. Plus, Defense Secretary Pete Hegseth reportedly shared sensitive information on Yemen strikes in a Signal chat with his wife and brother. And Pope Frances dies at 88 after a stroke. Sen. Sheldon Whitehouse, Laurence Tribe, Sen. Mark Kelly, and Sister Simone Campbell join Lawrence O’Donnell.