(CNN) – It was a tense moment on an emotionally charged topic: the daughter of the slain principal of Sandy Hook Elementary School asking Sen. Kelly Ayotte why, in mid-April, she voted against bolstering background checks on gun sales.
"I'm just wondering why the burden of my mother being gunned down in the halls of her elementary school isn't as important" as inconveniencing gun sellers, asked Erica Lafferty, daughter of Dawn Hochsprung.
If it looked like a made for television moment, it should. Lafferty was sent to Ayotte's event by the organization Mayors Against Illegal Guns, one of several gun control groups using this week's Congressional recess to bring the gun control message to the states.
The April 17 defeat of a bipartisan measure expanding background checks to gun shows and internet sales was seen as a major blow to gun control efforts, which began after the Newtown shooting in December that left 26 people dead. The new gun laws are a major initiative of President Barack Obama's second term.
After the vote, Obama called out senators who opposed the background checks bill, suggesting they were ignoring the will of the people who elected them.
Noting polls that showed 90% support for such a measure, Obama called it a "pretty shameful day for Washington" and wondered of Congress: "Who are we here to represent?"
WATCH: Erica Lafferty will appear Wednesday night on CNN's "Anderson Cooper 360," starting at 8 p.m. ET.
But while he vowed to continue pressing for tighter controls on guns, Senate Majority Leader Harry Reid ultimately shelved the gun control legislation without bringing it to a final vote.
However, there are discussions among senators to revive gun legislation, multiple sources say. One Senate source said even Ayotte is "willing to consider alternatives" to the background checks measure.
Senate Democratic leadership sources say they are willing to return to the gun issue, but only if they come up with legislation that is guaranteed to pass. Outside groups sending advocates to senators' events and running ads may help get there.
Those groups hope pressure from constituents will help fuel another go at gun control. Ayotte, who represents a state that voted for Obama in November and whose four other statewide representatives are Democrats, has been a particular target.
The group founded by former Rep. Gabrielle Giffords and her husband began airing radio ads accusing Ayotte of "ignoring the will of the people."
A spot from New York City Mayor Michael Bloomberg's Mayors Against Illegal Guns takes a similar approach, charging Ayotte with giving "criminals a pass" – a hard blow for the former state attorney general who ran largely on her tough-on-crime record.
And Organizing for Action, the political outlet formed from Obama's presidential campaign, took out ads online encouraging supporters to "Remind Senator Ayotte: You work for New Hampshire, not the gun lobby."
That gun lobby happens to be on the air in New Hampshire as well, praising Ayotte for her "no" vote on background checks. The National Rifle Association's radio spot thanks the senator for her "courage to oppose misguided gun control laws that would not have prevented Sandy Hook."
A survey conducted by a pro-Democratic polling firm indicated a drop in support for Ayotte after her vote against the background checks provision, along with other senators who opposed the measure. One, Sen. Jeff Flake of Arizona, wrote on Facebook earlier this week his new approval rating "probably puts me somewhere just below pond scum."
"It was a popular amendment, and I voted against it," Flake wrote. He'll be the subject of a protest organized by Bloomberg's group on Thursday, when survivors of gun violence will gather at his Phoenix office to demand a face-to-face meeting discussing the vote.
The poll also indicated a drop in support for other opponents of the bill, including Alaska's Mark Begich, one of the four Democrats from pro-gun states who sided with most Republicans in opposition.
Another one of those Democrats, Sen. Max Baucus of Montana, will soon be the subject of a television spot from the Progressive Change Campaign Committee that features a woman detailed her harrowing experience of hiding from an armed intruder.
"I hid my girls in a closet, called for help, aimed my handgun at the door and waited," Claire Kelly of Stevensville, Montana, says in the ad. "Guns can protect us but we're less safe with guns in the wrong hands."
The group said Wednesday they'll spend $50,000 to air the spot in Montana – even though Baucus announced in April he won't seek re-election in 2014.
"Another vote will happen in the Senate," Adam Green, PCCC's co-founder, said. "Max Baucus needs to choose whether he stands with the overwhelming majority of Montanans who support background checks or the gun manufacturers that profit by selling guns to criminals."
The ad isn't the only effort to highlight Baucus' vote. Bloomberg's group organized a "shame on you" rally at the senator's office in Bozeman shortly after the vote, part of a national effort to loudly protest senators who helped defeat the measure.
Mayors Against Illegal Guns will also send the father of a Newtown victim to Arkansas Thursday to attend a public event held by Sen. Mark Pryor, a Democrat who voted "no" on background checks and is up for re-election next year.
Meanwhile, national polling still indicates a desire for extending background checks on gun sales. Nearly two-thirds of Americans said in a Gallup survey out Monday that the Senate should have passed the measure in mid-April.
But the survey indicated a partisan divide, with Democrats and independent voters not seeing eye-to-eye with Republicans.
Prior to the Senate's failure to pass the proposal, most national polling indicated that nearly nine in 10 Americans supported expanded background checks for gun sales.
CNN's Dana Bash, Ashley Killough and Paul Steinhauser contributed to this report.