Student activists from Parkland, Fla., quickly mobilized after the shooting at Marjory Stoneman Douglas High School, becoming a vocal force calling for tighter gun laws. That movement led to mass “March for Our Lives” demonstrations around the country in March.

Student activists from Parkland, Fla., quickly mobilized after the shooting at Marjory Stoneman Douglas High School, becoming a vocal force calling for tighter gun laws. That movement led to mass “March for Our Lives” demonstrations around the country in March.