NRA membership is down! Gun sales are also down, and that's even more important since the NRA is funded by gun manufacturers as an 'advertising' effort.
After every mass shooting during the Obama admin., gun lovers ran out and bought more guns, because they expected new legislation coming soon that would limit their choices. This was good for the industry and so good for the NRA. But with Trump in office and Republican majorities in Congress, gun people KNOW there's not going to be new regulations passed, so there haven't been big spikes after gun crimes. The stock prices of the gun companies tell the sad story.
There's a theory that when Trump talked about taking guns away from unsafe owners ' . . and we can do Due Process later', that he really meant this as an ad for the gun companies.
I saw a huge cluster of ads for the NRA on YouTube in the last few weeks. They've disappeared now. Trump and the GOP have made it clear (in case it wasn't all along) that they're not going to do anything. But each multiple shooting shakes their foundations a little more, and cracks are showing up and propagating. I think they see the writing on the wall.
The NRA used to be all in favor of reasonable gun control. In fact the participated in getting many regulations and restrictions passed back before they decided to become hardcore and extreme. There's thought that they may return to their more reasonable, more realistic positions in the future.