I think the gun control people speak for me more than the NRA. They all have a role in the national discussions and policies. The NRA likes to try to speak for all gun owners, or at least pretend they do, but their choices are at odds with the opinion of most of their members, let alone most gun owners. The best way I can think of to combat their influences is to point out that they do not, in fact, speak for me even if they say they do and want to.
Of course many of the gun control groups do the same thing with those who advocate for more or different gun control measures (like me again!). They claim and try to speak for 'those for gun control', but they almost all keep making choices at odds with their members, the general public, and in my opinion what is good for advancing the issue.
So while they (the control groups and the NRA) claim and try to speak for me, and many people believe that they do, the fact is they do not. Sadly that is not as important right now as the fact that many people do believe it, so in effect they do get the influence as if they did.
It's...confusing.