Ft Hood: Registered Democrat/Muslim.
Columbine: Too young to vote; both families were registered Democrats and progressive liberals.Read rest HERE.
Virginia Tech: Wrote hate mail to President Bush and to his staff.
Colorado Theater: Registered Democrat; staff worker on the Obama campaign;
Occupy Wall Street participant; progressive liberal.
Connecticut School Shooter: Registered Democrat; hated Christians.
Common thread is that all of these shooters were progressive liberal Democrats.