Bush-1 and Bob Dolt also lost to Bubba-1 for that very same reason. Bush-1 is the one who used executive orders to create the magazine bans,bans on importing surplus military weapons (even American M-1 Garands coming back!,and closed the machine gun list. I think it can be safely said that he was the original prominent politician pushing for the future ban on so-called "Assault Weapons". Bob Dolt lost because he refused to allow the repeal of the AWB to come up for vote in the Senate,even after it passed in the House,and there were enough Senate votes to pass it. Dolt didn't want to take a chance on losing any of the gun-grabber votes,and thought he would get the votes of the gun owners regardless.
I don't know what needs to happen to change Republican Party Leadership, but if trends continue it won't matter what party's in office since neither will support the Second Amendment.
IMHO, it's good to have as many Republicans in power as possible provided that there aren't so many RINOs that the Republican leadership goes leftward. It may well be better, though, to have the Senate split 55% Dem, 15% RINO, and 30% conservative than 35% Dem, 35% RINO, and 30% 30% conservative. In the former case, the conservatives would have strong enough control over the Republican Party that the party itself could filibuster anything bad the Dems tried to put through. In the latter case, the party's leadership would go along with the bad stuff and so the Dems would be able to pass it even with "only" 35% of the vote.