Partisan is a good part of our Republic
I am interested in more of what the OP thinks, as are others here. The OP seems to be looking for support rather than opposition, however. For example:
"I know that many, in fact most, THR members will disagree with this point of view, and I respect that. I would be interested to hear if there are any other members here who support responsible gun ownership but are turned off by the NRA."
So, Owlnmole, you respect those who have opposing positions but are looking for supporters of your opinion. This action and deliberation of yours is exactly how Madison expected men to be when helping to support our constitution. Refer to
http://federali.st/10. Focus on the following part especially:
"There are again two methods of removing the causes of faction: the one, by destroying the liberty which is essential to its existence; the other, by giving to every citizen the same opinions, the same passions, and the same interests.
"It could never be more truly said than of the first remedy, that it was worse than the disease. Liberty is to faction what air is to fire, an aliment without which it instantly expires. But it could not be less folly to abolish liberty, which is essential to political life, because it nourishes faction, than it would be to wish the annihilation of air, which is essential to animal life, because it imparts to fire its destructive agency.
"The second expedient is as impracticable as the first would be unwise. As long as the reason of man continues fallible, and he is at liberty to exercise it, different opinions will be formed. As long as the connection subsists between his reason and his self-love, his opinions and his passions will have a reciprocal influence on each other; and the former will be objects to which the latter will attach themselves. The diversity in the faculties of men, from which the rights of property originate, is not less an insuperable obstacle to a uniformity of interests. The protection of these faculties is the first object of government. From the protection of different and unequal faculties of acquiring property, the possession of different degrees and kinds of property immediately results; and from the influence of these on the sentiments and views of the respective proprietors, ensues a division of the society into different interests and parties."
Madison goes on to conclude that faction in thus a part of our nature as humans. So when you favor supporting the non-profit part in lieu of the "partisan attack dog" you simply support raising a faction to combat the power of that one. You become another player in the partisan game.
Isn't our system great?!! We get to be humans! Humans carry guns, pick fights for reasons other than the sexual drive, wear buttons, kill others out of revenge for perceived wrongs done, blow things up for fun, play the political game of spamming, pandering, lobbying, etc. with other humans who do the same. In short, we aren't sheep. The more you find that an organization, administration, or campaign is trying to get you to act like sheep, the more you should thank those who fight for your Second Amendment right to strike down a single minded tyranny should it finally arise.