“We tried to be as diverse and broad as possible for how we built this plan,” said Charlie Mirsky, 19, one of the group’s founders. “We reached out to students, experts, every kind of demographic possible to make sure that we had the most comprehensive plan.”

At least 40 people worked on the plan directly, according to Ariel Hobbs, a member of the group’s student executive board. They collaborated through phone calls, in shared documents online, and face to face at a summit meeting last month in Houston.

Like the Green New Deal, the Parkland group’s proposal is a road map for legislative action rather than the legislation itself. “This isn’t a bill; it’s a plan,” said Mr. Mirsky, who has led the group’s lobbying program in Washington.

Ms. Hobbs added that lawmakers “can take the parts they want.”

“It’s not our job to pitch what they want to implement,” she said, “but we’re offering solutions to every single avenue of gun violence.”

The group never seriously considered a more gradual approach. “We kind of decided, at the end of the day, what are we doing if we’re not pushing for the strongest possible plan we can have?” Mr. Mirsky said. “We want to save the most lives that we can. We didn’t have a real choice.”

Ms. Hobbs, a student at the University of Houston, added: “There are always going to be people who say that we should wait, that we should take things slow. But while they’re saying that, people are getting killed.”

The Parkland group is hoping its plan will influence the political debate around the 2020 presidential election, and is asking each candidate to endorse it. It has also set a goal of mailing voter registration cards to all Americans when they turn 18.