Where did you get the headline? Referendum 71 was approved with a 51% vote margin.
And its not gay marriage, its same rights as a married couple, which is why they called it the everything but marriage bill.
While it might not be gay marriage yet, Sen. Ed Murray, the openly gay Democrat who authored SB 5688 states this is but an incremental step to overturning DOMA and giving gays fully recognized and legal same sex marriage in the state.
Approving this measure basically approves same sex marriage, just a little bit later on.