MSNBC'S Ari Melber hosts "The Beat" on Monday, May 10, and reports on the GOP's efforts to oust Cheney, the federal probe into Rudy Giuliani, and the DOJ investigation into Rep. Gaetz. Melber also debuts the newest edition of "The Summit Series," a series of in-depth interviews with leaders at the summit of their fields. MSNBC's Neal Katyal joins.