(St.Paul, MN)  --  The parents of a gay soldier killed in Afghanistan are urging Minnesotans to vote no on the marriage amendment in November.  Jeff and Lori Wilfahrt (WIL'-fert) of Rosemount helped launch the Veterans United campaign today (Tues) at the state Capitol.  Lori says people who enlist in the military take an oath to protect the Constitution - but this amendment would actually restrict freedom for some people.  She says they felt compelled to participate in the campaign because their son died protecting the Constitution.  Thirty-one-year-old Corporal Andrew Wilfahrt was killed in an insurgent attack in February of 2011.