Part of the problem is going to be that citizens of states will probably get no help from the feds on this.
SCOTUS seems to feel that registration is not an infringement and was unaddressed in Heller or McDonald (the question wasn't asked and this court doesn't make many extraneous comments). I don't know what they would do if you tried to claim that the state is making you pay to exercise a Constitutionally recognized right. I don't trust this court -- even with 5 who appear to 'sort-of' support 2A rights.
I believe the only hope for preserving - or restoring - rights is for a sufficiently large number of people to make sure elected officials are afraid to infringe lest they lose at the next election.
People don't like to be meddled with. We tell them what to do, what to think, don't run, don't walk. We're in their homes and in their heads and we haven't the right. We're meddlesome.--River Tam