1. Virginia Democratic State Senator, Phillip Puckett resigned on Monday, tipping the legislative balance in favor of Republicans and leaving Governor Terry McAuliffe's plan to expand Medicaid under the ACA hanging in the balance. Joining All In to discuss are Huffington Post's Washington Bureau Chief, Ryan Grim, The Washington Post's Michael Laris, and Virginia Del. Mark Sickles.
2. Chris Hayes is joined by political reporter and host of Ralston Reports, Jon Ralson, to discuss the implications of the shooting in Las Vegas on Sunday.
3. Chris Hayes weighs in on the "genuinely vile" speculation surrounding freed POW Bowe Bergdahl's captivity and release.
4. There are as many as 1,500 immigrant minors being detained in a facility in Arizona for trying to cross the border into this country on their own. Joining All In to discuss the operation is Immigration Reporter at La Opinion, Pilar Marrero.
5. In an article for New York Magazine, Jonathan Chait argues that President Obama has achieved all of four points of his ambitious policy agenda. Co-founder of Dream Defenders, Phillip Agnew joins All In.