UPDATE Below.
We don’t have the precinct maps yet, but I found the breakdown of Proposition 1 votes by legislative district on the King County Website. Semi-official illustrator of STB Oranviri generated this map for your viewing pleasure:

Note that the results apply to the King County portions of the districts only; in many cases only a fraction of the district was eligible to vote on the measure.
The results, in tabular form, are below the jump. A big pat on the back to the 36th district (Ballard, Magnolia, Belltown) who supported Prop 1 overwhelmingly, despite those neighborhoods largely not being served by light rail.



