Bernie Sanders and Hillary Clinton react as they speak during the CNN Democratic Presidential Primary Debate at the Brooklyn Navy Yard on April 14, New York.
Marissa Johnson, speaks as Mara Jacqueline Willaford stands with her and Sanders stands nearby as the two women take over the microphone at a rally on Aug. 8, 2015, in Seattle. The women, co-founders of the Seattle chapter of Black Lives Matter, took over the microphone moments after Sanders began speaking and refused to relinquish it. Sanders eventually left the stage without speaking further and instead waded into the crowd to greet supporters.
Sanders speaks at a rally, Aug. 9, 2015, at the Moda Center in Portland, Ore.
Sanders supporter shows off his tattoos at a rally at the Presidio on June 6 in San Francisco.
Sanders gives the crowd a victorious gesture on stage during a primary night rally in Concord, New Hampshire on Feb. 9 after winning the state's primary.
Sanders meets 3-month-old Oliver Lomas, of Venice, Calif., who was dressed as Sanders during a rally at Bonanza High School on Feb. 14 in Las Vegas.
Sanders greets "The Late Show" host Stephen Colbert in New York City, June 23.
Barack Obama walks with Sanders down the Colonnade during their meeting at the White House in Washington on June 9. Sanders met with Obama after Hillary Clinton has already effectively clinched the Democratic nomination.
Presidential candidate Hillary Clinton and Sanders stand together during a campaign rally where Sanders endorsed Clinton in Portsmouth, New Hampshire, July 12.