From the vantage point of Portland, Measure 26-199 looks like a slam dunk. The regional planning agency Metro aims to bite into the area's housing shortage by raising $653 million in property taxes and using the money to build as many as 3,900 new units of affordable housing in three counties: Multnomah, Washington and Clackamas.

There's no disputing that more low-income housing is needed in a metropolitan area where the apartment vacancy rate hovers below 5 percent.

But history suggests only one of these three counties can be relied upon to vote for new property taxes: the blue bastion of Multnomah County. The last couple of times Metro asked voters for big money—an open spaces bond in 2006 and a zoo bond in 2008—voters in Washington and Clackamas counties responded with far less enthusiasm than did Multnomah County voters. And Metro was already running parks and a zoo—it's never been in the housing business. (In fact, Metro is the only elected board in the country that handles planning for a three-county area, which is how it ended up with this project. It would hand these dollars to local housing agencies.)

Portlanders approved a city housing bond with 63 percent of the vote in 2016. They'll need to be even more enthusiastic this time, to counteract the more conservative voters of Washington and Clackamas counties.

Early polling on the idea of a Metro housing bond showed only 54 percent of voters supported a $500 million bond. Then Metro increased the size of the measure to $653 million, drawing opposition from Washington County Chairman Andy Duyck and his allies.

The good news for Metro? Their foes have so far raised just $34,000 to fight the bond.

But even in sky-blue Portland, the bond's backers may see a weakening of support. Portland's tight housing market is starting to loosen up—and that could reduce some of the enthusiasm for government housing subsidies. As WW reported in August, a glut of high-end apartments has arrived on the market faster than people want to rent them. That's left developers offering as many as two months free rent in some buildings.

To be sure, those deals are slow to trickle down to people living on the edge of homelessness. On the low end of the market, apartments are as scarce as ever.

Developers aren't just seeing the market softening. They're also skeptical governments and non-profits can provide housing more efficiently than they can—and they're privately grousing about bureaucratic red tape.

"I'm hearing very soft support from the development community, because we're in a regulatory environment where it's harder to make projects work in the city of Portland," says Portland developer Robert Ball, who's still undecided on the measure.