He then pulled up on my right and told me that when the light changed, I better stay out of his way because he was turning left and if I got in the way, he'd run me down.
oh my god! a motorist actually verbally threatened you? that's crazy!!! there sure was something they could do-- question him, tell the motorist he had no right to be angry, as cyclists are supposed to be riding on the streets with cars, a verbal threat against anyone is still unacceptable (in ontario, i believe, even a threat of assault is still againt the law. rarely enforced though, i think it's mostly for stalkers, etc. )... but basically, yes, there was a lot they could do, they just didn't want to. either they're lazy, or don't care about cyclists, or they are ignorant themselves.

how long ago was it? maybe ask your local bike club if they can help. some cycling groups have websites you could raise a stink on, or a media person who could get a local station involved. ...if you think it's worth it that is-- being angry takes a lot of energy, and in the end you might be in the same place anyway.

i complain about toronto, but it looks like some parts of the states are very close-minded regarding cyclists. i always ride streets, simply because there are no convenient bike paths for my commute, but i've only had a few incidents-- and even then they were mostly when i was newbie, and i acted like a walking target...

but yikes! i'd have hated to be in that position.