Bernie Sanders pledges to help Joe Biden defeat Trump in 2020

Bernie Sanders and Joe Biden took a significant step toward uniting the Democratic Party when Sanders endorsed his former 2020 rival for president. The two politicians said they are forming joint task forces on issues including health care, immigration and climate change. Sanders announced his support on a video call between the two that was broadcast online, throwing support behind Biden three months earlier than when he backed Hillary Clinton in 2016. Ed O'Keefe explains what Biden's latest endorsement means for the campaign trail.