“Yeah, but if you want to complain about the casual treatment of guns in movies, you don’t have to look very hard on any Friday night,” said Senator Chris Murphy of Connecticut. Murphy hasn’t seen the movie, but he’s one of Congress’s leading advocates of gun-control regulation. It’s not the world’s most rewarding job. In recent years, his colleagues have not only refused to pass an extremely modest bill on background checks, they’ve failed to ban the sale of guns to people on the terrorism watch list.

“American Sniper” is on one, supremely obvious level, a celebration of gun culture. But it’s also a cautionary tale. The real Chris Kyle was shot to death while the script was being written. He had volunteered to help a troubled veteran, Eddie Ray Routh, who had a history of violent behavior and was an apparent victim of post-traumatic stress. Kyle felt the best way to get him to relax was to take him to a shooting range. While they were there, Routh turned his gun on Kyle, and one of Kyle’s friends, killing them both.

“American Sniper” could actually be seen, at least in the final scene, as a good-gun, bad-gun message. The real Chris Kyle did enjoy walking around the house, twirling a pistol. His wife said that as the clouds lifted after his Iraq service, he would playfully point a gun at the television and pretend to shoot down the bad guys.

Jason Hall, who wrote the movie screenplay, said the scene was meant to both show Kyle in recovery and presage the violence that was about to occur off-screen.

“There’s a tension in the scene that builds toward the ending,” he said in a phone interview.

The American gun lobby has pushed its cause so far that it, too, may be falling off a cliff. Texas, where Chris Kyle’s alleged murderer is going on trial next week, has always had a gun-friendly culture, so much so that visitors can bring concealed handguns into the State Capitol. Some people definitely do not think this goes far enough, and, on opening day of the Legislature last month, they demanded new laws making it legal to carry handguns in the open, preferably without a license.