Here in Arizona, and the other gold star states, and in many if not most parts of the other states, the cops have an understanding of the fact that while we might not exactly be their friends, we are not their enemies, and just like them, non cop gun owners support the common good.
While I certainly won't discourage anyone from being a volunteer cop, because it's a great way to help your community if you feel the urge, I don't think it has the potential to further our cause broadly. The thing is, we are their partners in supporting peace, because us gun owners are ready to protect ourselves and others if a violent criminal should attack us or others. If they can't understand that as it stands now, I doubt that joining them since we can't beat it into them will help.
Don't get me wrong, it might help in a few really anti gun departments, if some of us were to volunteer, gain their respect, then tell it like it is, but for the most part, I just don't see it.