A vote today with a kind of milestone. On one side the nra with their power and money and a lot of republican backing. On the other side, families of newtown, connecticut, wielding the power of their... See More
A vote today with a kind of milestone. On one side the nra with their power and money and a lot of republican backing. On the other side, families of newtown, connecticut, wielding the power of their grief. The issue is this. Would republicans block a vote on any kind of gun control? Today the families won a small victory. Here's jeff zeleny. Reporter: It's been 118 days since ben wheeler was killed at sandy hook elementary school. And today, it was his face -- the face of a 6-year-old -- looking over the senate floor at as lawmakers voted to begin the most significant congressional gun debate in two decades. They defied republican leader and delivered a rebuke to the nra, which has fought hard against new restrictions on gun owners. David and francine wheeler, ben's parents, had been urging senators to take this vote all week. As they sat in the senate gallery, ben's ashes hung in a silver necklace around his mother's neck. When we caught up with the wheelers when they started their lobbying trip earlier this week, they said they knew the road would be long. I'm by no means an expert on the machinations of the senate. It's a byzantine process. Reporter: After the vote, president obama called to congratulate the families. The senate will now debate a bill next week that would expand background checks for purchases at gun shows and online sales. But that's far less than the president wanted. A measure to ban assault weapons and high-capacity magazines has nearly fallen from the conversation. Jillian soto, whose sister was one of the teachers killed in newtown, is not done fighting. Shy plans to be back on capitol hill next week. There's some stuff I wish we had stronger, but I am happy that we are getting somewhere with it. Jeff zeleny, abc news, capitol hill.
This transcript has been automatically generated and may not be 100% accurate.