It has been 20 years since two heavily armed young men in dark trenchcoats entered a Colorado high school and launched a bloody attack that seared the word “Columbine” into the American psyche, forever transforming the debate on gun rights and school violence.
As people on Saturday prepared to mark the anniversary of the massacre in Littleton, Colorado — in which teenaged shooters Dylan Klebold and Eric Harris killed 12 Columbine High School students and a teacher before turning their guns on themselves — there were words of grief and loss and anger.
The events of that fateful day planted a jarring and lasting sense of vulnerability in Americans’ minds.
School shootings, once almost unheard of, have become a tragic feature of American life — requiring all schools to tighten security, forcing even six-year-olds to take part in traumatic “live-shooter” drills.
Places that had always seemed the safest — schools, libraries, even churches and synagogues — no longer seem so.
A rededication 
But as folks in Littleton prepared for an official memorial service Saturday, there were also words of hope and signs of a rededication to making things better.
Saturday was the third annual…