As Will Riley watched students stage this year’s walkouts for gun control, he grew frustrated with the message that his generation was somehow united against the Second Amendment. “I’m seeing people saying, ‘We need to do something, we’ve got to enact some kind of legislation because this is for the kids.’ Well, I’m also the kids, and I don’t like that,” Mr. Riley told the Washington Times. “And there are other people like me. The other kids haven’t spoken yet.” The 18-year-old senior from Carlsbad High School in Carlsbad, New Mexico, decided to do something about it by launching Stand for the Second, a May 2 school walkout designed to give a voice to “the other kids,” namely those who support the Second Amendment. “We’re getting generalized. Our generation’s being defined,” said Mr. Riley, whose website is StandfortheSecond.com. “And I think we have an obligation to define ourselves.” Stand for the Second comes as the first national student walkout aimed at supporting gun rights in the aftermath of the Feb. 14 mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida, which touched off a wave of campus gun-control activism. Mr. Riley is encouraging students to stage 16-minute walkouts on campus after coordinating with local police and working with school administrators to make sure the protests don’t conflict with testing. So far, walkouts are being planned by students in about 300 schools from 42 states, based on the online map operated by Tea Party Patriots, which is helping Mr. Riley with organization.