I personally see both parties, in the whole, as being interchangeable. I suspect some of the issues one side is "for" are simply a result of that party wanting to be the opposite of the "con" side, and not really about the issues themselves.
(Note I did not specify which party, nor which issue.)
I think a lot of what goes on, does so simply to distract us from other realities. While we here focus on gun control, for instance, how many billion dollars in aid get sent to Syria, Egypt, and Pakistan?
So to me it is entirely conceivable that a lot of the gun control fight is political theater to distract the masses, with collusion from both major parties.
That said, the NRA is NOT a political organization, per se, and for sunaj to think it is the job of a pro-gun organization to act as clearinghouse for politics as a whole...
Well, put it another way, I doubt Planned Parenthood endorses many party line Republicans, even though there are many pro-choice Republicans in the US; the party line types will not be openly pro-choice, unless they are willing to relegate themselves to never having influential committee positions and to enduring primary challenge after primary challenge. I don't fault Planned Parenthood for that reality.
Similarly, sunaj et al should not fault the NRA if (at present) most pro-gun politicians are Republicans.
How much of that is due to true individual beliefs, or to truly held party beliefs, or merely to the role chosen in that particular bit of battle theater by each party's leadership is another issue, entirely.