The crowd is attending the National Rifle Association convention and knows it's coming. They go prepared to cheer. The message they cheer is profit over people, bullets over ballots and gun law over civil law. Then they get together and complain that the left wing press and the left wing zealots misinterpret the message. They complain that a leftist press obscures knowledge of the civil involvement that's the basis for NRA programs, teaching gun safety to youngsters and promoting sports shooting.
Zealotry is as zealotry does, whether from the left wing or the right wing.
If the NRA group were truly interested in promoting sportsmanship, they'd have told Heston and Wayne LaPierre to stay home. From the beginning, their stage would have been crowded with youngsters and their B-B guns, trap shooters promoting their sport and game sportsman speaking of safety, maintaining good relations with landowners and the preservation of game animals. But this isn't what they do, and no longer what they're about. They're about rebuilding the declining profits of the arms industry and supporting politicians who will do the gun industry's bidding. Then they spin the constitutional proposition that the public has no right to legal protection from the senseless carrying of weapons in public places.