Last year, one piece of housing legislation overshadowed all others. Senate Bill 827 by state Sen. Scott Wiener (D-San Francisco) would have allowed developers to build four- to eight-story apartment buildings next to public transit stops around the state.

The goals were laudable: Ease regulations on the construction of desperately needed new housing (the state acknowledges it is short 3.5 million units), and reduce commuters’ greenhouse gas emissions by placing more homes near greener transportation such as subways, light rail and bus stops.

The method was radical: Take away some of the zoning power of cities, which traditionally decide what types of homes can be built where and don’t typically encourage apartment buildings to be built right next door to single-family homes.

The instant controversy over the bill made national headlines. Beyond enraging homeowners in anti-growth locales such as suburban South Bay and Marin County, anti-gentrification groups complained the bill lacked sufficient protections for tenants in low-incomes communities where new high-rises often equate to rising rents.

So despite support from urbanists and environmentalists nationwide, the bill died a loud and early death. Wiener vowed he would be back with a similar plan next year, because he saw it as the only way to fix the state’s crushing housing shortage.

Well, it’s back. This week, Wiener and California YIMBY (“Yes In My Backyard,” a pro-development group mostly of younger Californians backed by tech money) unveiled SB 50. “The heart of the bill is the same as where the bill ended up last year,” said Wiener. “This is about adding housing and not replacing existing tenants.”

Under the proposal, in most cases cities would no longer be able to block new apartment buildings within a half-mile of public transit. Developers also wouldn’t have to worry about minimum parking requirements, which otherwise could add costs and reduce the number of apartments in a building.

But changes in the new version of Wiener’s legislation have made it more palatable to some, and attracted new political allies. Certain communities that already created effective transit-oriented development plans would be exempt—which is why Los Angeles Mayor Eric Garcetti, a foe of last year’s bill, supports this one.

Garcetti and various Los Angeles anti-gentrification groups feared last year’s bill would encroach on their own plans to bring more affordable housing to public transit. While singling out Garcetti’s program, details on what other local initiatives might be exempt from the SB 50 remain unknown.

While details remain in flux, the bill also includes a provision for more low-income housing and stricter protections for tenants, an attempt to mollify concerns from anti-gentrification groups who remain wary, but are not as explicitly opposed as they were last year. “There was certainly more engagement prior to SB 50 than before SB 827, and we definitely appreciate that,” said Anya Lawler, a policy advocate for the Western Center on Law and Poverty, who testified against last year’s bill. Lawler’s organization is waiting to see how key affordable housing provisions are fleshed out in the coming months.

Perhaps most importantly, the bill has a powerful new ally—organized labor. The State Building and Construction Trades Council, which opposed Wiener’s bill last year, endorses the new legislation. The “trades” and their campaign coffers wield enormous clout in the Capitol, and were instrumental to passage of a 2017 housing bill package.

“The entire approach is different,” said Cesar Diaz, legislative and political director with the state construction workers’ union. “It’s a collaborative approach by a senator who brought us in to work on this early on.”

Why the about-face?

Diaz says language in last year’s bill was too ambiguous about which types of projects could qualify for expedited city review. The new bill is clearer—most projects will still need to submit to an environmental review and conform to local labor standards, allowing construction workers’ unions to wield more influence in local project approval. “Nothing in the bill will reduce labor’s ability to get wage protections,” Wiener said.

Even with the backing of organized labor, Wiener’s kinder, gentler “upzoning” bill still faces its own uphill climb. State Sen. Jim Beall, current (although perhaps not future) chairman of the Senate housing committee, did not vote for last year’s bill. This week, he issued a press release signaling he may be preparing an alternative to Wiener’s approach.

Most California cities—although not all—have loathed this approach because it strips their zoning power. A new provision promoting denser development in higher-income communities seems particularly provocative. “Job rich” communities—a term Wiener has yet to fully define, but ostensibly applies to cities such as Palo Alto and Cupertino with more jobs than employed residents—would incentivize denser development even in areas not within a half mile of public transit.

The provision aims to ensure that new apartment buildings won’t be built only in lower-income neighborhoods with lots of bus stops, but also in wealthier enclaves with lots of job opportunities but little public transit.

A remaining variable is Gov.-elect Gavin Newsom, who applauded Wiener’s ambition but was lukewarm on the details of last year’s legislation. A spokesman for Newsom declined to comment on the new bill.

CALmatters.org is a nonprofit, nonpartisan media venture explaining California policies and politics.