PHILADELPHIA, PENNSYLVANIA - APRIL 07: Democratic presidential candidate Sen. Bernie Sanders (D-VT) speaks during the AFL-CIO Convention at the Downtown Sheraton Philadelphia on April 7, 2016 in Philadelphia, Pennsylvania. The Pennsylvania primaries will be held on April 26. (Photo by William Thomas Cain/Getty Images)
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PHILADELPHIA, PENNSYLVANIA - APRIL 07: Democratic presidential candidate Sen. Bernie Sanders (D-VT) speaks during the AFL-CIO Convention at the Downtown Sheraton Philadelphia on April 7, 2016 in Philadelphia, Pennsylvania. The Pennsylvania primaries will be held on April 26. (Photo by William Thomas Cain/Getty Images)
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