Don't forget the gigantic highway lobby and GM's role in funding the destruction of rail in cities across the country. Remarkably successful strategy. Eventually were convicted iirc, but it was too late.
The subways there went bankrupt from the fare cap as the city had some obsessive need to take over the subway systems.
Cars didn't pay anything for road wear, and they didn't (and still don't) pay anything towards congestion. They clogged the streets, made streetcars slower, and essentially freeloaded.
Utilities were forced to divest from streetcar ownership, which forced the streetcar companies to pay retail electricity prices instead of wholesale ones.
At the time GM came around, public transit was already hurting. GM was able to do what they did because the companies were hurting and could be bought cheaply.