Bmel17,
I would recommend you check out the NRA "system" you refer to, and you will see that they grade candidates only on their 2nd Amendment stance, their questionaire, and record. They are not interested in any other political platforms or subjects other than 2nd Amendment Rights. There is also a grading system by The Gun Owners Of Americs (GOA), the second largest firearms advocate group. Grading runs fairly consistant.
For gun owners, Democratic candidates usually run poor grades, as so many are part of the anti-gun lobby. They feel that they know better than you about the right to bare arms and self protection, and want to take that Constitutional Right away from you and me. That cannot be allowed to happen. It happened to the Jews in Europe many years ago and they were rounded up by the millions and killed, because they had no self-defense. Historical fact.
As I under stand it, there are already things in place by the Obama Administration, if he wins a second term, to move to remove firearms from private citizens. They do not believe in the right to bare arms by private citizens. Only police and military. Sounds like Hitler to me.