As housing affordability and inequality become national political issues, the people who have long dominated those meetings are starting to see their anti-development agenda upended. Cities are gaining political traction for policies that once seemed out of the question. The newest tool that cities are deploying in the ongoing fight against segregation and housing inequality is to let their streets get denser, in what is known as upzoning. Making zoning more progressive still faces awfully long odds, though, which makes this strategy a question of policy and politics.

....

The idea driving all these projects is simple: When developers are legally allowed to build more kinds of housing, more of it will conceivably be built. Especially for cities strapped for affordable housing, this increase in housing stock is attractive as a path to lower costs. For the cities jumping on the densification train, however, no single one-size-fits-all solution has surfaced. Every specific fix chosen by cities is up for debate1—and still subject to the anti-development preferences of vocal blocs of primarily wealthier, whiter, homeowner residents.

“There’s this belief that if you just get rid of single-family zoning, it's the Mecca,” said Seattle Mayor Jenny Durkan. “And I just I think you’ve got to do more to really make it work right.”

....

• 1. Upzoning faces stiff resistance from the left, ... A frequent criticism from the socialist set holds that permitting more housing doesn’t necessarily mean more affordable housing, especially if developers are left to their own, market-influenced devices. In California in particular, tenants’ rights groups have expressed the fear that giving developers freer rein to build taller will result in more displacement, not more accessibility. Given the intense demand for housing, increasing density only a little—or upzoning just in neighborhoods where it’s cheaper to build—could make matters worse.