That's fine the NRA does that and I understand why. I'm not voting for Koster no matter who endorses him.
Koster has been a crappy AG. He also put a fascist idiot hoplophobe in charge of 2A in the AG office who gave out a lot of bad info to citizens the first year of Koster's term. He pays a lot of lip-service and appearance of 2A support but underneath he is a progressive fascist before all else. There are plenty of other negatives from his time as AG.
I just look at it this way ... Jay Nixon was a very good AG. The only (D) I have voted for multiple times.; He applied the law equitably, even when he didn't agree with it. When CC passed, he put pro-2A guys in charge of reciprocity and, according to both of them and the results they achieved, he stayed out of their way and didn't interfere with fair application of the law. BUT as governor, he hasn't give 2 squats about equitable application of law. He was almost impeached because of ignoring the law and turning private citizen records to the fed in violation of MO laws. I didn't and wouldn't vote for him for governor or any higher office.
Koster in contrast is already a biased, inequitable law applying failure in the AG office. I cannot imagine promoting him.
Of course, similarly, Kander has screwed up the Sec of State's office and also wants a promotion.
Voting against Koster and Kander is a no brainer. They both deserve to be fired, not promoted.