DeRay McKesson, the activist who gained national fame as a leading voice in the Black Lives Matter movement (and for his superb appearance on Late Night With Stephen Colbert recently) is running for mayor of Baltimore.

McKesson filed his application to run in the democratic primary just minutes before the 9 p.m. deadline tonight, The Baltimore Sun reports. Since Baltimore pretty much always elects a Democrat as mayor, the primary will likely determine the winner.

McKesson, a 30-year-old former public school administrator, had given no hint of his plan to jump into the race before filing his surprise application.

He started making a name for himself as an activist when the Ferguson protests over Mike Brown started in the summer of 2014. Today McKesson has a Twitter following of more 300,000 people and has met with top White House officials and presidential candidates.

McKesson used Medium to publish an 800-word statement on on why he's running for mayor. 

"In order to achieve the promise of our city and become the Baltimore we know we can become, we must challenge the practices that have not and will not lead to transformation. We must demand more from our leaders and local government. ...

"At its core, being the Mayor is about having a vision for the city that is both aspirational and grounded in reality. It is about demonstrating the ability to turn intentions into reality and maintaining the fortitude to see our ambitions met with strong implementation."

In the wake of Freddie Gray, issues of race and justice will be huge in predominantly-black Baltimore electing its next mayor. The current mayor, Stephanie Rawlings-Blake, is not running for re-election.