NEWTOWN, Conn. (AP) — Despite a year of setbacks, the parents of children lost in the Sandy Hook Elementary School massacre insist they won't lose the fight to reduce gun violence.

After 12 months of personal suffering and political frustration, they have become key players in an effort to pressure Congress to adopt changes ahead of next fall's elections. They're backed by organizations that are sending dozens of staff into key states, enlisting thousands of volunteers and preparing to spend tens of millions of dollars to try to influence congressional campaigns.

Last Dec. 14, a gunman using a military-style assault rifle killed 26 people inside Sandy Hook Elementary, including 20 first-graders.

Congress has enacted no new gun curbs since the shooting. And the national gun lobby seems as strong as ever, if not stronger.