Last Fall Dow Constantine was elected to fill the vacated position of King County Executive. The position he left was that of King County Councilmember. Both positions are non-partisan. Both positions required the county council to fill the position.
For The interim position of County Executive, before Constantine was elected, while he was still a councilmember, the council had a majority of Democrats. They were able to fill the executive position with a Democrat.
When Constantine was elected to be the executive he vacated his council position. The council was split, 4 Democrats to 4 Republicans, and struggled to agree on who should fill the council vacancy.
The executive and council positions are officially non-partisan. In a partisan position the party officials nominate 3 people to select from, in a non-partisan position there isn't an official connection to the elected position.
What to do (other than revert back to positions)?
Winding its way through the Washington State Legislature is SB 6688: Concerning filling vacancies in nonpartisan elective office.
This bill passed the Senate on February 10th. It is due for a Hearing on the House side on February 19th is Scheduled for public hearing in the House Committee on State Government & Tribal Affairs at 1:30 PM.
The essential change in the law will be that a "non-partisan" executive, or a "non-partisan" commissioner, will nominate 3 people to be picked from by the council. If a person is not selected within 30 days from the date of the vacancy then the partisan governor must a select someone within 15 days.
So, 45 days could laps before somebody fills an empty and non-partisan King County Council position, filled by a partisan officeholder.
I am not sure how a partisan can appoint somebody to a non-partisan seat. I would not be shocked to see this logic tested in court.