Former landlord giving negative reference--what can I do?

I lived at a house for about 8 years and was basically a model tenant. When I moved out, the landlord wrongfully withheld my security deposit. I had caused NO damage to the house. I had to take him to small claims court to get my deposit back. I won my case and the judge ruled against the landlord, and he had to refund my entire security deposit. Now, he is giving me a bad reference for any new rental property I am applying for. As a result, I can't get a place to rent--my application is getting declined every time! What can I do? Do I have any recourse against this former landlord?