The Libertarian Party candidate for President, Bob Barr, on the other hand, was a member of the NRA's Board of Directors. He also has an A+ rating with them.
Enter Sarah Palin, a lifetime member of the NRA and now the Republican nominee for Vice President. She is well known in conservative circles for her staunch support of gun rights. Certainly selecting her is reassuring to the NRA.
While I'm not suggesting that the NRA's endorsement of a Presidential candidate was the only factor in McCain picking Palin, the mere possibility that they might have endorsed Barr very well could be a much bigger factor than the mainstream media and the Republican Party will ever admit.