“The tone around gun violence is really not in their favor right now,” Mr. Bernstein said. “You can’t just sit silent and do ‘no comment.’ That just doesn’t work while people are dying.”

Mike Kuczkowski, the chief executive of Orangefiery, a communications strategy company, said on Monday that the N.R.A. “has been very adept in knowing when they didn’t need to intervene.”

But in the wake of the Parkland shooting, there has been a rise in high-profile student activists who have been able to influence the debate about guns, Mr. Kuczkowski said.

“That’s been a remarkable thing for us to see who have been following this conversation over the decades,” he said. “If I were in the N.R.A.’s shoes, I would take that seriously. I would want to rally the base.”

On Sunday, Mr. North said television and movies helped promote violence but also blamed medication.

“If you look at what has happened to the young people, many of these young boys have been on Ritalin since they were in kindergarten,” he said.

Ritalin and other stimulants used to treat attention deficit hyperactivity disorder are not known to produce violent behavior, experts said.

“The odds that a medication like this is going to be associated with an act that took weeks or months to prepare is slim to none,” said Dr. Steven P. Cuffe, chairman of the Department of Psychiatry at the University of Florida College of Medicine in Jacksonville.