contact Jim hacking. check him on YouTube and he'll let u know the procedures and if you can sue or not and base on testimony he sue them so many times for his clients and they get approved quick but every cases different just check him out on YouTube watch his videos and if u feel comfortable get the number and reach out to him him. he is good at it

California - yes. USCIS is sued all the time and right now there're some more suits against them. you can file the Mandamus. it takes a few months to allow for each part including USCIS to respond accordingly. you need a lawyer for that. the Mandamus forces them to deliver a decision (denial or acceptance) with explanation on why they're dragging their feet and why they're denying if they're denying. best of luck. 🙂