First step to a more progressive tax scheme, which eventually will require some kind of statewide income tax, would be to pass a city-wide measure under consideration to overturn an outdated 80-year-old legal precedent. It would only apply to unearned income (capital gains, dividends, interest) from households with an AGI of quarter million dollars or more.
Anti-tax groups will sue immediately, which will give the WA Supreme Court a chance to align our state with the 44 others that already support some kind of income tax. One side benefit would be replacing the funds that the Trump Administration has threatened to withhold on account of being a sanctuary city. www.trumpproofseattle.org