Stefan Sharkansky has a wonderful post on the fight for charter schools in Washington, outlining the chance for passage this legislative session. He lists the historical supporters and opponents, which bolsters his thesis that the primary opponents are teachers unions and administrators who are afraid of losing their benefits. Given that charter schools give parents more control over their children's education and that they have been established successfully in 40 states, I support his call to pass legislation enabling their creation in Washington.
How to make it happen? As Stefan notes, the best way is to contact the legislators in your district. In Washington, each district has one senator and two house members, so you have three people you can get in touch with. In case you don't know who represents you, there is a handy page to find your state representatives on the Washington State website. Just type in your address and you'll get links to all three.
By the way, it is find to send email or make a phone call, but send a letter if you have the time. Letters from constituents are a big deal and are taken seriously. At a minimum, expect a form letter acknowledging receipt of your letter and having some statement about how the member intends to vote on the issue.
As always, be courteous when writing. Let him or her know that the issue is important to you, but don't threaten to vote for his or her opponent if you don't get your way. No one responds to threats well, and the member is smart enough to read between the lines. It is better to treat him or her as an old friend and build up a rapport with regular, thoughtful correspondence.