About half a year ago, Bernie Sanders's campaign was off to a rough start with racial justice activists — Black Lives Matter protesters were interrupting his rallies, demanding that he speak out about criminal justice issues, and characterizing the supposedly progressive candidate as weak on an increasingly important issue in the Democratic coalition.

On Thursday, we got a huge sign of just how much things have changed: Sanders was endorsed by the daughter of Eric Garner, the unarmed 43-year-old black man who died after a New York City police officer put him in a chokehold.

The very emotional video, produced by the Sanders campaign, tries to adapt Sanders's message — of a political revolution against the elite and powerful — to the criminal justice system and racial justice.

Erica Garner argues, in between clips of Sanders discussing racial disparities in the criminal justice system and calling to hold police accountable, "I believe Bernie Sanders is a protester … He's not scared to go up against the criminal justice system. He's not scared … And that's why I'm for Bernie."

Sanders will certainly find a big set of interest groups to fight in the criminal justice system: Unions for police, prison guards, prosecutors, and other actors in the criminal justice systems, along with private prison companies, are strong supporters of the status quo and tough-on-crime laws.

But this is also a smart, timely political pivot. Not only does it follow famed racial justice writer Ta-Nehisi Coates's statement that he'll vote for Sanders, but it also precedes primary elections in the critical states of Nevada and South Carolina, which are far more diverse than the states that have voted so far.

After Hillary Clinton effectively tied Sanders in Iowa and lost big in New Hampshire, her campaign has been hoping that the diversity of the next few states would play in her favor, due to her much broader support among minority voters in polls so far. But Sanders is making an effort to change that demographic math. We'll see if it works.