You're only thinking of direct political contributions, as opposed to levies & fees that the local TLCs get from the taxi companies that they don't get from Uber.
One example - in many cities Verifone provides the credit card swipes in the taxis along with a convenience fee of 8% and a surcharge. Much of that fee goes to the TLC. Cabbies hate it, but that's the monopoly game. With Uber, there's no similar fee that gets paid to the TLC and cabbies and consumers aren't gouged for a simple credit card transaction.
I don't buy the lack of interest in Buffalo & Rochester as the reason, since many smaller cities do allow Uber. Buffalo & Rochester get the short end because they reside in a nanny state where the pols don't want to lose a revenue stream, and there isn't enough consumer blowback. The other states with similar demographics as Buffalo & Rochester didn't care enough to put up stupid roadblocks.