Changes demanded by Sen. Bernie Sanders supporters now have broader backing.
The Democratic National Committee chairman has had a rocky relationship with the activist left.
A “unity commission” proposal will strip two-thirds of superdelegates of their power to vote independently.
DNC Rules Committee Passes 'Unity' Resolution Calling For Commission On Super Delegates And Caucuses
The Sanders campaign is celebrating the commission's creation.
They lost in the rules committee, but they'll get another shot on the convention floor.