In this photo taken July 26, 2015, Sen. Bob Casey, D-Pa. speaks during a news conference on Capitol Hill in Washington. Supporters of the Iran nuclear deal are on the cusp of clinching the necessary Senate votes to keep the contested agreement alive and hand President Barack Obama a major foreign policy victory in spite of furious opposition. Democrats Casey and Chris Coons of Delaware on Tuesday became the 32nd and 33rd senators to announce support for the deal, just one shy of the 34 votes needed to uphold an Obama veto of GOP legislation aimed at blocking it. (AP Photo/Andrew Harnik)