Seattle is officially on its way to considering a city income tax.

The Seattle City Council today unanimously approved a resolution setting out a timeline for considering a city tax on high-earners. The council plans to have have a draft ordinance by May 31 with the goal of passing it by July 10. (Today's vote was 8-0; Council Member Debora Juarez was absent.)

Given current court precedent in Washington state, a city income tax is all but guaranteed to end up challenged in court—and that's the whole point. Supporters see passing the tax in Seattle as an opportunity to push the decision to the state Supreme Court. If the tax reaches the state high court, they hope judges will overturn the rulings and laws currently keeping cities from taxing high earners. The resolution says that the council's "primary consideration" in crafting a city income tax will be its "legal viability." (Read more about the steep legal challenge ahead here.)

Key details, like the rate of the tax, who will pay it, and what it will fund, remain undecided. One pitch from a local coalition called Trump-Proof Seattle proposes taxing income in excess of $250,000 per household at 1.5 percent. (In other words, if your household makes $300,000, you'd pay the tax only on $50,000.) They say that would raise about $127 million a year and affect the top 5.1 percent of Seattle residents.

Council Member Lisa Herbold, who sponsored today's resolution, cited reports ranking Washington's tax system as the most regressive and least transparent and said there is "absolutely no evidence that having an income tax is an impediment" to economic growth.

Council Member Lorena González, who has ignored requests for comment about whether she supports a city income tax, indicated today she's comfortable with the using a city tax as a test case.

“Lawyers do this all the time. As a people’s lawyer, I did this all the time. The facts of many of my cases were complex, messy, and not always clearcut," González said. "It is in those moments that policy makers like lawyers must muster the will to challenge unjust laws… Our regressive tax system is not exempt from this principle."

One speaker during today's public comment identified himself as During public comment, speaker Ned Friend said he's an engineer at "a local tech company" who would qualify for a high-earners tax and would be "honored" to pay it.

“In my circles, almost everyone feels the same way," he said. "We the wealthy want a wealth tax."

Katie Wilson, the general secretary of the Transit Riders Union who has helped lead the Trump-Proof Seattle coalition, said her organization has put "boots on the ground" year after year to support transit measures in the region.

"We’ve done that despite the fact that the taxes that have funded those measures have been regressive taxes," Wilson told the council, "and, you know, we’re really tired of that. That’s why I and my fellow Transit Riders Union members are thrilled to be here today."

Some city council members, like Herbold, have worked closely with Trump-Proof Seattle, but others have avoided taking a position. By voting on the resolution today, the full council indicated they're at least willing to talk about a city income tax as a legal test case, but that doesn't guarantee they'll all support it when the time comes. Council Members Tim Burgess, Debora Juarez, and Lorena González have not responded to requests from The Stranger about their position on Trump-Proof Seattle's proposal, and Council Member Sally Bagshaw was noncommittal. The remaining members of the council—a majority—have indicated at least tacit support.