Ask Uber and the similar services currently embroiled in legal battles in NYC and LA how "no one" cares about taxis politically. Changing incumbents isn't so simple

Or just note that medallions cost hundreds of thousands of dollars (or more). If taxi drivers were politically powerless, why on earth would that be the case?

taxi driver != medallion owner

They will be up against enormous headwinds, though. Unions have power, but it's not infinite, and society's willing to tolerate the unions is going to balanced against the cost of the tolerance... and in this case, after the self-driving cars are about 5 to 10 years in and the cost of making a self-driving car is minimal compared to leaving the hardware out, the price pressure on the unions is probably going to just steamroll them.

If you have trouble with that idea, look at the history of the UAW. Unions are not infinitely powerful, and the further above "market price" they're trying to price their services, the worse off their position becomes.

Unions make headway because human labor is a component that is needed in the completion of the product/service.

Once they are replaced by cost-effective automation, there is little to no leverage they have.

I work in a start up that has to do with taxi and limo in germany. The limo market is not very political, the taxi market is. Its one of the most distortet markets I have seen. In Berlin you have a state set taxi price.