You can't build a lot in the bay area without affecting people who have a large personal stake in the housing market. That is the core of the issue in any major city with high housing prices. One of the few ways you can work around that is by building high speed transit. Since building in those newly connected locations will be in a different market or political region.

Another way is to take away power from the people who own housing and give it to people who are struggling to live or move there. With state or federal power.

I don't think it unreasonable that you are the one who has to make the case how that would work in this discussion. Because I see very little evidence, in the US or even in the rest of the world, that it would be realistic to expect that to happen. If anything high prices is often a result of going the other way (by e.g. favorable tax rules).

Why would anyone build family housing or buy it there then?

Renting sure. But purchasing house means a lot more than "this is my square". Amenities, schools, the community are all directly tied to what your house is worth and it is an investment.

If I'm putting down a million dollars on a house and you decide my local gov. elected representatives are going to be superseded on local governance I'm not going to be very happy.

Lol. Your vaunted local representatives are superseded on everything from their airspace (FAA) to their property tax rate (California Prop 13). This isn’t some unprecedented infringement of local control.

Lol there is a precedent for the regulations in place that you are after to be handled locally. Lets just take all the things and federalize it until I get my way.

Perhaps you could clarify about what "take power away from those who own housing means". Does it mean, own a house, lose the right to vote?

(1) What makes you think that the areas adjacent to the central valley rail stations will allow housing of a reasonable density

(2) "You can't build a lot in the bay area without affecting people who have a large personal stake in the housing market" ->Tons of people with a large personal stake in the bay area are being displaced by rising rents. Do they suddenly not count because they do not own a home?

1. It isn't a given, but far more likely since they don't have the same disincentive. Attracting companies and tax revenue is generally something cities like to do. Alienating a large part of their population isn't. Especially not the wealthier parts.

2. I don't know about suddenly, but that would otherwise probably be an accurate assessment of the situation. At least relative to those who do.

Is there any western city, or a political party, who have intentionally lowered property values in the last decade and been awarded for it by voters? Has anyone even tried?