I forget the exact language of the Board of Directors' statement (October 1996 issue of American Rifleman), but the implication was that if someone on the ballot is sufficiently anti-gun, you must support the person's opponent regardless of whether he's really pro-gun.
As soon as I read that statement, I sensed trouble. Shortly after it was published, I saw usenet postings from Gun Owners of America talking about the Lautenberg Act that would be coming up for a vote, but the NRA never said a peep about it.
Would the Lautenberg Act have received the support of all but two Republicans in the Senate, and IIRC the majority of Republicans in the House, about a month before an election no less, if such politicians didn't think their opponents were bad enough the NRA wouldn't do anything about them?
You're going to have to ask yourself the question, if those other gun groups are so important and powerful, Why didn't they stop the bill?
At least Gun Owner's of America tried. The NRA didn't even do that much.