Benjamin Franklin famously said "in this world only two things are certain, death and taxes." If I may be so bold to add, I would say once a tax is implemented, it always grows in scope and burden. 

Such will be the case with the pending capital gains income tax - which advocates try to deflect its nature by falsely labelling an "excise tax." As the state Supreme Court prepares to hear the legal challenges made against the tax, it is paramount that they see clearly what every single other state in the country and the IRS have illumined: a capital gains tax is an income tax. 

Matt McIlwain and Collin Hathaway put it even better in their new op-ed in the Seattle Times, saying:

 The state also claims that this new tax is a legal “excise tax” on personal income from capital gains. The problem is that an excise tax is typically paid on things like retail sales, gas or liquor and collected where the items are purchased. But this new tax is on your income earned anywhere, which means it’s an illegal excise tax that would follow you wherever you go. Or to put it another way, it’s like Washington state charging you an additional gas tax on gas you bought in Oregon or any other state! 

The op-ed also highlights the contradictions between supporters justifications for the need for the tax and reality, as well as illuminating the ugly road it will likely continue down. This excellent op-ed is available to read here, and I would highly encourage you to do so.