Charlie Kirk founded Turning Point USA when he was a teenager, connecting naturally with his core audience to build a youth organization. He has been credited with helping swing the Gen Z vote toward President Donald J. Trump last year.

“No one understood or had the heart of the youth in the United States of America better than Charlie,” Mr. Trump said last week, after Mr. Kirk was shot and killed on a college campus in Utah.

In death, however, Mr. Kirk is reaching new generations.

Sonya Buckhannon, 52, a sales rep who lives on a barrier island off Charleston, S.C., sent a message to Turning Point USA days after Mr. Kirk’s death asking how she could get involved with the group’s work, possibly by starting a chapter for parents and grandparents in her area.

“With his death, people are recognizing they weren’t the only ones who felt that way,” she said. “There are lots of people in my generation who are here to be advocates for him.”

Across the country this week, parents and grandparents said that watching young people’s intense grief over Mr. Kirk’s public assassination has prompted older conservatives like themselves to look seriously at his work for the first time.