I'm with the NRA. I don't see them rushing into federal courts to test the applicability of the 2A as it applies to the states. they are content with the structure we seem to have now - states making choices (notably on CCW) through their elected bodies, with only the most draconian "all guns are illegal" state laws which would be worthy of taking into federal court.
I'm not fully up to speed on the history of this - was the Brady Bill ever challenged in federal court?
The NRA is not going to endorse Rudy.