I think political purposes, vs crime & accident prevention perhaps as the obvious alternative. Obviously there could be conflict even with these two broad categories but most historical things will be easy to drop in one bucket or the other at this point. (Certainly even the opossers above would not argue that the nazi gun laws were for cime/violence/accident protection?)  For modern issues where there is live debate, we can place the arguments of each side in the appropriate section (with appropriate WP:DUE weight of course.