Why we’re still fighting over voting rights, 50 years on

Fifty years ago, the Voting Rights Act outlawed discriminatory practices used to stop Americans from casting a ballot. President Obama marked the occasion with civil rights leaders, cautioning that those rights are still at risk. Gwen Ifill talks to Imani Clark, a student at Prairie View A&M University, voting rights scholar Kareem Crayton and Zoltan Hajnal of University of California, San Diego.