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.

Randi Weingarten announced plans to exit the Democratic National Committee (DNC). Weingarten, the president of the American Federation of Teachers

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.