I have no evidence one way or another on whether this will pass, so I'm curious as to what you're basing your assessment on.

The local NIMBYs have virtually no power at the state level, so I don't see how they could block this.

Whereas real estate developers, construction companies, and construction trade unions do have lobbyists in Sacramento.

I'm not sure that real estate developers are super-excited to build projects with 20% on-site affordable units, though maybe! I think it's clear that their preferred model would be to allow them to off-site their affordable housing requirements, but maybe this is a compromise they could live with.

20% affordable is standard in many places, especially since affordable isn't really that affordable.

Note the difference between "affordable" and "on-site affordable."

Those requirements are quite common in Texas and developers still build like crazy.

They turn around and donate some cash to an "affordability" fund to get out of building any affordable units in their new developments. I'm somewhat torn about this: something has to be done to insure that a variety of economic classes live and mix in proximity in our cities ,but it seems like affordability programs don't do much to help the working poor but offer plenty of assistance to folks who are on disability and other assistance programs perpetually.

Despite my radical leftist beliefs, I feel like the family that works in the downtown should be able to live "close" to their work if they want to, with an available pool of affordable housing in the market.