If you're a Republican, you may gotten your ballot and thought to yourself, "Why bother filling that out? I mean, Donald Trump is the last candidate standing. He's assured of getting the nomination, right?"
That's true. But Trump doesn't have the 1,237 delegates he needs to win, yet. And the Washington State Republican Party uses the primary to allocate 100 percent of its delegates to the National Convention based on the primary results. So if you vote Republican in the Washington primary, your vote counts.
Democrats, not so much. They use the March caucuses – not the primary – to allocate delegates to their national convention.
Nevertheless, Secretary of State Kim Wyman encourages you to vote. She says the primary is a chance for voters to express themselves. So, if you want to express yourself, all ballots must be returned or postmarked by May 24th.