Protesters are gathering in Washington for the "March for Our Lives" rally, demanding stricter gun control measures. The protest is led by survivors of the Florida school shooting last month, which left 17 dead and 17 others wounded. The rallies are aimed at breaking through a legislative gridlock that has long stymied efforts to tighten firearms controls. Organizers want lawmakers -- many of whom are up for re-election this year -- to ban the sale of assault weapons and tighten background checks for gun buyers.