Survivors, victims' families remain vocal gun control advocates
Nightclub shooting remembered as protesters descend on D.C.
Gunman killed 49 people inside gay nightclub in 2016
Rubio criticized over gun control, LGBT rights
Christine Leinonen criticizes Marco Rubio over gun control
Victims' families, friends struggle to cope with tragedy
Mother of Pulse nightclub massacre among attendees
Featured speakers included Sen. Tim Kaine and Rep. John Lewis
Florida Republican announced re-election bid after nightclub massacre
Christine Leinonen spoke at gun control rally in D.C.
