The Lake Stevens Democrat will chair the Senate Transportation Committee.
Kirk Pearson resigned earlier this month to accept a job in the Trump administration.
Brian Baird and Chris Vance unveil a new organization called Washington Independents.
Lawmakers must act during the next legislative session to satisfy the state Supreme Court.
The changes are the result of the Democrats regaining the majority in the Senate.
A Manka Dhingra win in the 45th District would give Democrats a 25-24 advantage in the Senate.
Some hope that a Democratic victory in the Senate race will spur a bipartisan Hirst compromise.