In a small victory for Bernie Sanders — and a big slap at Hillary Clinton and the national party establishment — Maine Democrats voted at Saturday’s state party convention to rein in the power of their superdelegates.

Maine superdelegates will no longer be free to vote as they please at the Democratic National Convention, starting in 2020.

Instead, they will be required to cast their ballots in line with the state’s caucus or primary results.

Maine Dems also voted to “urge” Maine’s five superdelegates to vote with the bound delegates in Philadelphia in July.