Simple marijuana possession charges now account for fully half of all drug arrests in Washington, according to the Democrats, who pointed out pot’s status as the second biggest cash crop in the state. reports Jonathan Martin at The Seattle Times.

The group said cannabis has the potential to raise $215 million in new tax revenues each year if a current legalization drive, Initiative 502, also known as New Approach Washington, passes.

I-502 is sponsored by the ACLU of Washington and endorsed by prominent figures including former U.S. Attorney John McKay (who was responsible for the prosecution of “Prince of Pot” Marc Emery), Seattle City Attorney Pete Holmes and travel host Rick Steves.

It is expected to gather enough signatures to go before the state Legislature in the upcoming session. At that point, the Legislature can either take action or, more likely, let the initiative be decided by the state’s voters on the November 2012 ballot.