Basically Tesla has been sued or had the law come up in almost every single state, and every single one basically has a unique legal exception or banning regarding them. Ranging from "zero-emission/electric gets a free pass" to "dealerships can't service the vehicles correctly so Tesla wins by being too complex." Wikipedia has an entire page just for the issue and its mostly listing each state's different setup.

If I had to guess, its a lot of that "electric/zero-emission" propaganda managing to convince a lot of lawmakers into giving them a loophole. Or getting a lot of bribe money using the various Green laws already on the books to pay those lawmakers.