Excerpted from Washington State Budget 101:

Washington’s tax code guarantees future revenue shortfalls

Because of Washington’s heavy reliance on the sales tax, budget revenue doesn’t match growing needs for education, health care and other public priorities. People are spending more on services, which are mostly not taxed, and buying more over the internet, mostly tax-free. Even as population and incomes go up, sales tax revenue does not keep up with the need for state services.