Tonight on The Last Word: National security experts sound the alarm over Donald Trump's debt. Also, Democrats tout President Biden's policy achievements in Arizona. Plus, the House Democratic Caucus elects Rep. Joe Neguse as Assistant Leader. And conservative media outlets try to explain away Trump's "blood bath" comment. Amb. Susan Rice, Andrew Weissmann, Sen. Mark Kelly, Rep. Joe Neguse, and Brian Klaas join Lawrence O'Donnell.