UNKNOWN LOCATION - APRIL 13:  In this screengrab taken from JoeBiden.com campaign website, U.S. Sen. Bernie Sanders (I-VT) endorses Democratic presidential candidate former Vice President Joe Biden during a live streaming broadcast on April 13, 2020. Sanders said,  “Today, I am asking all Americans—I’m asking every Democrat, I’m asking every Independent, I’m asking a lot of Republicans—to come together in this campaign to support your candidacy.”  (Photo by JoeBiden.com via Getty Images)