WASHINGTON

SENATORS say they fear the N.R.A. and the gun lobby. But I think that fear must be nothing compared to the fear the first graders in Sandy Hook Elementary School felt as their lives ended in a hail of bullets. The fear that those children who survived the massacre must feel every time they remember their teachers stacking them into closets and bathrooms, whispering that they loved them, so that love would be the last thing the students heard if the gunman found them.

On Wednesday, a minority of senators gave into fear and blocked common-sense legislation that would have made it harder for criminals and people with dangerous mental illnesses to get hold of deadly firearms — a bill that could prevent future tragedies like those in Newtown, Conn., Aurora, Colo., Blacksburg, Va., and too many communities to count.

Some of the senators who voted against the background-check amendments have met with grieving parents whose children were murdered at Sandy Hook, in Newtown. Some of the senators who voted no have also looked into my eyes as I talked about my experience being shot in the head at point-blank range in suburban Tucson two years ago, and expressed sympathy for the 18 other people shot besides me, 6 of whom died. These senators have heard from their constituents — who polls show overwhelmingly favored expanding background checks. And still these senators decided to do nothing. Shame on them.

I watch TV and read the papers like everyone else. We know what we’re going to hear: vague platitudes like “tough vote” and “complicated issue.” I was elected six times to represent southern Arizona, in the State Legislature and then in Congress. I know what a complicated issue is; I know what it feels like to take a tough vote. This was neither. These senators made their decision based on political fear and on cold calculations about the money of special interests like the National Rifle Association, which in the last election cycle spent around $25 million on contributions, lobbying and outside spending.

Speaking is physically difficult for me. But my feelings are clear: I’m furious. I will not rest until we have righted the wrong these senators have done, and until we have changed our laws so we can look parents in the face and say: We are trying to keep your children safe. We cannot allow the status quo — desperately protected by the gun lobby so that they can make more money by spreading fear and misinformation — to go on.

I am asking every reasonable American to help me tell the truth about the cowardice these senators demonstrated. I am asking for mothers to stop these lawmakers at the grocery store and tell them: You’ve lost my vote. I am asking activists to unsubscribe from these senators’ e-mail lists and to stop giving them money. I’m asking citizens to go to their offices and say: You’ve disappointed me, and there will be consequences.

People have told me that I’m courageous, but I have seen greater courage. Gabe Zimmerman, my friend and staff member in whose honor we dedicated a room in the United States Capitol this week, saw me shot in the head and saw the shooter turn his gunfire on others. Gabe ran toward me as I lay bleeding. Toward gunfire. And then the gunman shot him, and then Gabe died. His body lay on the pavement in front of the Safeway for hours.

I have thought a lot about why Gabe ran toward me when he could have run away. Service was part of his life, but it was also his job. The senators who voted against background checks for online and gun-show sales, and those who voted against checks to screen out would-be gun buyers with mental illness, failed to do their job.

They looked at these most benign and practical of solutions, offered by moderates from each party, and then they looked over their shoulder at the powerful, shadowy gun lobby — and brought shame on themselves and our government itself by choosing to do nothing.

They will try to hide their decision behind grand talk, behind willfully false accounts of what the bill might have done — trust me, I know how politicians talk when they want to distract you — but their decision was based on a misplaced sense of self-interest. I say misplaced, because to preserve their dignity and their legacy, they should have heeded the voices of their constituents. They should have honored the legacy of the thousands of victims of gun violence and their families, who have begged for action, not because it would bring their loved ones back, but so that others might be spared their agony.

This defeat is only the latest chapter of what I’ve always known would be a long, hard haul. Our democracy’s history is littered with names we neither remember nor celebrate — people who stood in the way of progress while protecting the powerful. On Wednesday, a number of senators voted to join that list.

Mark my words: if we cannot make our communities safer with the Congress we have now, we will use every means available to make sure we have a different Congress, one that puts communities’ interests ahead of the gun lobby’s. To do nothing while others are in danger is not the American way.

Gabrielle Giffords, a Democratic representative from Arizona from 2007 to 2012, is a founder of Americans for Responsible Solutions, which focuses on gun violence.