Two union leaders and longtime Democratic National Committee members have resigned from the national party, marking the latest internal dispute of chairman Ken Martin’s tenure. The departures of American Federation of Teachers leader Randi Weingarten and Lee Saunders,

Randi Weingarten, head of one of the nation’s most influential teachers unions, and Lee Saunders, the president of a large union of public workers, each pointed to Ken Martin’s leadership.

Randi Weingarten, President of the American Federation of Teachers (AFT), announced in a letter dated June 5 that she would be leaving her position