Of course there's a way to fight it. But those laws are usually in place for the protection of the animals. It is difficult and expensive to properly care for many animals. We know YOU care for all your cats - but can you say the same about your neighbors? Does your city have licensing laws? Are your cats licensed? And because you care for ferals - are they "your" cats?
To change city laws, you lobby city counselpeople. Call your city hall, find out who and where to write or call them. But I personally would find out about the larger picture. Mandatory licensing laws can wreak havoc for feral caretakers. I'd find out what all the city laws are re: animals, shelters and animal control, and I'd work on changing the whole she-bang, so to speak.
BTW - don't forget. You might find some useful materials on www.StrayPetAdvocacy.org
if you want to lobby the city for low-cost spay/neuter programs and TNR as alternative and cost-effective feral cat management.