Apparently it wasn't really killed by the local populace. There is narrative about how it would have caused sprawl-like development (certainly a conservative mindset in context). I couldn't find any references to that for Marin though. It seems what did it in for Marin at least was a campaign from the GG Bridge district, fearing a loss of power and money; there was strong support in Marin for BART (https://books.google.com/books?id=z56Ui3QFYPgC&lpg=PA136&ots...).
My father was an Electricain on BART. I remember those dinner conversations about bringing BART into Marin County.
The reason it didn't come through Marin was cost. It might have been political, but I don't believe that was the case. It did seem seems like politicians were much more corrupt than they are today? We had absolutely no way of finding out what they were up to; except for good, honest newspaper reporters.
At the time, the project was incredibly expensive to build. Every foot of track was scrutinized. The people of Marin would have loved to have BART go through their county, especially the SF commuters.
My father's biggest grip was getting to a job site from Marin to San Francisco. He hated the commute, along with myself years later. I guess we were spoiled? The commute was only 45-60 from Marin to anywhere in the city.
At the time, building BART was really a big deal. The enginneers would load materials into these huge round cylinders. Welders would then run beads around the circumfrence of the cylinders. Once everything was secured to to ocean floor, workers from the SF? side would cut into the new section. As a kid, I was allowed to go to work with my father once a year. I would drive electric golf carts up and down the tube.
Times have certainly changed? For some reason, Electricians drank a lot back then? Actualy everyone drank a lot back then. It was not uncommon to see a Electricain drinking a beer down in those dark, dank, tubes--if they had a stationary boring job to do. I recall my father building a lamp from one of the third rail insulators, and I still can't get rid of a "Danger--3rd rail sign" he lifted. On the sign, right after Danger, they put in Pelligro. They actually debated whether it was necessary to put in any foreign language on the signage. It was a different time; Marin and San Francisco were 90% white, mutt, middle class, and Hispanic people were scarce.
I do miss the man, but we had our differences. He always felt that because I went to college, I would turn into some pompous a-hole? I told him, "Dad, I'm going to a state college. I said, "It's actually kind of a joke, but I do want to graduate." He didn't have to pay a dime for my education, so I still don't know what his problem was? It's almost like he wanted me to be happy, but just not happier than himself? Well he won? I remember a christmas card he gave me that had a bunch of "PhD, Doctor, too many degrees, etc." before my name on a card. I went home, from that Christmas dinner, and had a nervous breakdown, and have never been the same. Thanks Dad! Different parenting skills back then?
88% of the people in Marin county wanted to extend BART there, according to polling done at the time. Bridge officials didn't want it, and shopped around for an engineer to until they found one who said the Golden Gate bridge couldn't handle the trains.
The "it'll cause sprawl" narrative apparently did not play much of a role in the actual politics of the planning process.
I guess it was all those right-wingers in Marin?