The Trump administration is pressed on its claim of Iran's "imminent threat." Also, Jeffrey Epstein's attorney faces the House Oversight Committee. Plus, James Comey is subpoenaed in a Trump Justice Department probe. And Lt. Gov. Juliana Stratton wins the Illinois Democratic Senate primary. Rep. Jimmy Gomez, Rep. Ro Khanna, Sen. Sheldon Whitehouse, and Lt. Gov. Juliana Stratton join Lawrence O'Donnell.