ArmyBratproud didn’t cause a rift - it was opened up by the NRA itself. The NRA chose the single-issue attitude to politics over objections by its membership. The NRA lost lots of members - including me - over their misguided endorsement of dingy harry. (actually what lost me was their intransigence to discussing political endorsement issues with their membership - they refused to answer our questions).
Thus, I see the question of “How many of these Democrats did the NRA give money to and get re-elected?” entirely valid and reasonable.
The NRA is and always has been a sinlge-issue organization. As an institution, they don't care about taxes, Obamacare or abortion. Their only concern is defending the right to keep and bear arms and they'll support the candidate with the best record of doing so regardless of their political party or where they stand on other issues.