"At 25 years old, Cameron Kasky is certain that he’s too young to be dealing with the back pain he’s been feeling. But the Democratic socialist and activist, who is announcing on Tuesday morning that he’s the latest entrant in a crowded primary to replace the 78-year-old representative Jerrold Nadler in New York’s 12th Congressional District, also thinks that the circumstances of his arrival in politics “fast-forwarded my aging a little bit.” At 17, Kasky, a survivor of the 2018 school shooting in Parkland, Florida, cofounded the gun-violence prevention group March for Our Lives. The work brought him to Capitol Hill to meet with lawmakers; it also led to his being swatted and doxxed."