by Patrice Taddonio

Two years ago this Sunday, 20-year-old Adam Lanza entered Sandy Hook Elementary School and killed 26 children and adults with a Bushmaster rifle before taking his own life with a handgun.

The tragedy shocked the nation, sparking an outpouring of grief and widespread calls from the public for politicians to “do something” about guns. The moment, it seemed, was gun control advocates’ to seize.

But, like many times before, they ran into intense opposition from a powerful political force: the National Rifle Association (NRA).

On Jan. 6, FRONTLINE explores the NRA’s history, political evolution and influence in Gunned Down: The Power of the NRA, an investigation from veteran FRONTLINE filmmaker Michael Kirk into how the NRA became such a successful lobbying force, and how it has consistently succeeded in defeating new gun control legislation.

Watch a clip from the documentary that goes inside the NRA’s response to Newtown:

For more of FRONTLINE’s reporting involving the Newtown tragedy and America’s gun debate, watch our collaborative investigations with the Hartford Courant — Raising Adam Lanza and Newtown Divided — and read our related stories at both films’ websites.

Gunned Down: The Power of the NRA premieres on Jan. 6 (check your local listings here).