This may have been posted on here before, but I haven't seen anything about it. Last night on History Detectives, which airs on PBS, they did a segment to find out why Cleveland killed its electric streetcars in the 1950's.
As it turns out GM, which was conspiring to buy up all of the rail lines across the country and convert them to busses, to be purchased exclusively from GM of course, got into some shady business with a former Cleveland Mayor. His name was Ray something or other and at the time was a county commissioner, who was also on the city's transportation committee. It was strongly implied that in exchange for a GM dealership in the city he voted to sell off our streetcars to Toronto and replace them with busses.
That is of course the short version. It was a pretty interesting 10 or so minute segment. Good stuff.