Transcript for Newtown Mother Delivers Obama's Weekly Address, Urges Gun Control Support

Now to the latest on the washington. This morning a mother who lost her child in the newtown school shooting stepping in for president obama delivering his weekly radio and internet address to the nation. This as republicans and democrats brace for one of the most heated gun control debates in decades. Abc's jeff zeleny is in washington with more. Good morning, jeff. Reporter: Good morning, bianna. The debate over gun control is a deeply personal one and the white house is hoping that the power of one family's story will help keep the momentum alive until next week when the senate begins its debate. This morning, americans expecting to hear president obama's weekly address instead heard this voice -- as u.S. Probably noticed I'm not the president. Reporter: That's francine wheeler. We have to convince the senate to come together and pass commonsense gun responsibility reforms. Reporter: Taking her very personal case of gun control from the halls of congress to the hearts and minds of americans. Your younger son ben, age 6, was murdered in his first grade CLASSROOM ON DECEMBER 14th. Exactly four months ago this weekend. Reporter: To keep momentum alive for its gun bill, the white house asked wheeler and her husband to share ben's story. Ben's love of fun and his excitement at the wonders of life were unmatched. Reporter: When we caught up with the piano teacher and her husband earlier this week going door to door on capitol hill they feared the senate would not act. But this morning both sides are bracing for the biggest congressional gun control debate in two decades. Please help uso something. Reporter: Even critics who are still pushing hard against the legislation say the efforts of the wheelers and other families are making a difference. I think there's been some impact. It's a very emotional issue. There are also parents of some of those victims who don't agree with a call for more gun control. Reporter: Francine wheeler knows the road ahead is long. Next week in the senate and beyond. I haven't yet passed any bills that will help keep guns ou the hands of dangerous people. And a lot of people are fighting to make sure they never do. Reporter: But, she says, the memory of her son will not let her give up. I feel ben's presence filling me with courage for what I have to do. Reporter: When I spent time on capitol hill earlier this week with francene and david wheeler it was clear how difficult it was for them to tell their story but they said this is something that they had to do. They know that this bill is just the beginning but this morning senate aides tell me the bill next week also could include a mental health component. That's something the wheelers and other families think is critical.

This transcript has been automatically generated and may not be 100% accurate.