Black Lives Matter power grab sets off internal revolt

The Black Lives Matter movement is buckling under the strain of its own success, with tensions rising between local chapters and national leaders over the group’s goals, direction — and money.

From the beginning, Black Lives Matter was a grass-roots effort, born in the streets with no central hierarchy. The idea: to keep power concentrated in the hands of its members, the people.

That’s changing. After a summer of protests that made Black Lives Matter a household name, those atop the movement are making a series of moves to alter...