Professor Newmark has done yeoman work on this story, including a quote from one researcher that sheds light on the story's persistence.
The GM conspiracy myth, understood in this way, makes a great deal of sense. It becomes irrelevant that GM did or did not cause or even contribute to the decline of mass transit in the U.S. What becomes compelling, from a larger perspective, is the manner in which the GM story is used, the political and economic climates in which it is most likely to emerge, and the types of policy initiatives under consideration during the periods in which the story is being told.The Democratic Underground poster that has touched off a lengthy thread has his own compulsion.
In a matter of a day, in some places, workers were forced to stop the use of trams, ultimately forcing the purchase of cars. They had no choice. It was forced capitulation and a segragation of those with the means and those without.The assertion is historically inaccurate. The trams -- streetcars, if you will; sometimes trackless trolleys -- were replaced with buses. The toiling masses would have the opportunity to board a bus at the same corner where the car stopped, and the bus offered the transit company the opportunity to more cheaply extend the route as the city expanded. (To this day, the Milwaukee bus network, which despite my long tenure in DeKalb, is still the network I am most familiar with, still uses the route numbers and central-city routes of the predecessor streetcars, although -- as one example -- the Holton-Mitchell Route 14 that in streetcar and trackless trolley days turned back at 43rd Street and Oklahoma Avenue now runs beyond 92nd Street.)
My own assessment of the case and of streetcar to bus conversions is here, with some related observations on the pace of conversion in National City and other cities here, and a canard sighting from someone who should know better is here.