Warren unveils new election security plan ahead of first debate; Sanders, O'Rourke, others unveil new policies, Democratic candidates about to face biggest test yet at first debate; Biden bracing to be attacked on his own record, Bernie Sanders on whether key Democratic group prefers Elizabeth Warren to him: "I don't care who they prefer", Sanders campaign adviser on Warren rivalry: Do people want originals or copies? "He's the original", Trump warns of "Obliteration" if Iran attacks U.S.; Iranian leader: White House is "Mentally disabled", Shocking photo shows migrant father and daughter drowned at the U.S-Mexico border, Democrats seeks breakout moment in first 2020 debate, Agriculture Secretary Perdue on climate crisis; "It rained yesterday, it's a nice pretty day today", Melania Trump announces her spokeswoman will be President's new Press Secretary, replacing Sarah Sanders, Trump: I'm joking about serving more than 2 terms (Is he?) via Knit