if they endorse an AWB ban, it's members will know that, and will leave. I know I will.
Well, good news - you'll have extra money in your pocket, because you won't be paying for for their dues. I'll guarantee you that they'll endorse any and every gun ban that comes down the pike, just as their website implied that it would, before they took the language down after succumbing to the heat. But I wish you luck and hope that you are right - I would be pleasantly surprised. The ONLY question is how long it will take for the issue to come up - 1, 2, 3, 4, 5, 6, 7, or 8 years? Or more.
And I take exception to your characterization of the NRA being mostly Republicans. While that may be technically true, that's not at all what they're about. And certainly not true in my case. There's no cause and effect there. This happens simply because so many people of the D party choose to run on anti-freedom platforms. It's the chicken and the egg, except that in this case, we KNOW which came first - the D party members chose anti-freedom positions BEFORE the NRA took a stance against them, and favored their pro-gun opponents (who just happen to be - usually but not always- members of the R party).
The AHSA is not any more of a substitute for NRA than death is a substitute for life.
If you want an alternative to NRA which is actually supportive of the RKBA, and pretty a-political, here's your answer (not AHSA):
http://www.saf.org/
The NRA doesn't endorse anti-gun republicans, but the AHSA endorses anti-gun Democrats.
EXACTLY; thank you. That one truism says all that you need to know about the situation, to debunk the idea that they are a "pro-Democrat yet pro-RKBA alternative to NRA".