The net revenue from the tax -- the state estimates it would produce $1.6 billion the first year and more than $11 billion over five years -- would be put in a dedicated trust fund for education and health programs, such as the basic health program for the working poor or vaccinations for children.

Nor might the trust fund be a lock box. Legislators could tap it to fund programs outside of education and health care.

The Washington Research Council says legislators have diverted billions of dollars to the general fund from other accounts.