13/06/2013 11:16 BST | Updated 13/08/2013 06:12 BST

America and Its Guns

Before she goes to bed every night, and on waking each morning, Nicole Hockley maintains a small but emotionally-charged routine. She kisses the urn of her precious son Dylan. She keeps the ashes in her bedroom next to his picture.

Dylan was the six year-old British boy gunned down in his Sandy Hook classroom, along with 19 other children and six teachers. He was found in the arms of his special needs teacher.

"It's my way of talking to Dylan," Nicole told me. "And of making sure that he would approve of the path I've taken."

That path is a draining, roller-coaster journey through the impossible politics of gun control.

Nicole wept with anger and disappointment when the US Senate voted against gun reform. Like several Sandy Hook family members, Nicole was watching from the Senate gallery.

Who could possibly object to a modest tightening of background checks, a measure that would help keep guns out of the hands of criminals and the mentally deranged? As it turned out, a significant number of Senators defied the formidable power of the Sandy Hook families in favour of the gun lobby.

I have followed some of Nicole's journey over the last six months. I first witnessed the courage of Nicole and Ian Hockley soon after the massacre, when they spoke of Dylan's infectious laugh and the horror of realizing that he wouldn't be coming home.

The Sandy Hook campaign has seen many disappointments since then, capped by that humiliating rejection in the US Senate on 17 April.

But I've also seen Nicole weep with relief and gratitude. On 8 May we were in Dover, Delaware, when the Governor signed into state law a tightening of background checks on gun purchases. Nicole's tenacious lobbying had paid off.

Somewhere in Delaware, at some point, a gun sale to a would-be killer will be denied as a result of this new law. A life will be saved. And even if we never know the identity of that person, Dylan Hockey's death will have meaning.

"Defeat is not in my vocabulary," Nicole insists. She compares her effort to that of Mothers Against Drunk Driving, calling gun control a cultural movement not a political campaign. Success won't be achieved in months but will be measured over a generation.

Washington has moved on in the six months since Sandy Hook. Over 5,000 gun murders have taken place since then, a toll greater than all the US deaths of the Iraq War. Those names are being read out today in front of the Capitol, a stinging rebuke to Senators who voted against reform.

The White House is investing little in keeping gun control on the political agenda. The Senate's legislative schedule is full. Immigration reform is the issue of the day.

But don't underestimate Nicole Hockley and her fellow Sandy Hook campaigners. They are learning fast the ways of Washington. They have no hesitation in leveraging their emotional stories of loss and grief. And they are promising their campaign for common-sense gun reform has only just begun.

America and its Guns: Tonight will be broadcast at 19.30pm on ITV 1