A month after the mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida, David Hogg stood in front of a crowd of hundreds of thousands gathered at the U.S. Capitol to demand an end to gun violence. “Who here is going to vote in the 2018 election?” asked Hogg, then a senior at Marjory Stoneman Douglas and co-founder of student-led group March for Our Lives (MFOL).