Members of the Black Lives Matter movement say that is a distinct possibility, depending on whether the Democratic nominee can repair a frayed relationship. “We are going to have very clear demands,” says Brittany Packnett, an educator and activist. “If those aren’t met, you may see people behaving in alternative ways. People may not show up to vote.”

In the activists’ eyes, each of the candidates must overcome checkered records on criminal justice. The 1994 crime bill signed by Clinton’s husband consigned a generation of blacks to lengthy prison sentences for nonviolent crimes. As mayor of Baltimore and later as governor, O’Malley took a zero-tolerance approach to community policing, sparking tensions that exploded into rioting last spring when 25-year-old Freddie Gray died of injuries sustained in police custody. Sanders touts his record of civil-rights activism, but as a member of the U.S. House of Representatives, he voted for the 1994 crime bill. Now a senator from an overwhelmingly white state, his campaign has largely focused on economic rather than racial inequality.

“There’s something insufficient about all of them,” says one activist associated with Black Lives Matter.