Whipple, one of the most powerful women in the General Assembly, is the second veteran northern Virginia lawmaker to announce she won't run. Last week, longtime Alexandria State Sen. Patcy Ticer announced she won't run again.
Whipple's announcement set off a series of tearful tributes on the Senate floor.
Whipple has served in the Senate since 1996 and was chair of the Democratic caucus there. She was the first woman to hold a leadership position in the Senate. Before that, she served on the Arlington County School Board and the Arlington County Board of Supervisors.