The NRA published a video in response to Davis, running circus-like music under the first part of the candidate's original commercial and suggesting Davis should clean his mouth out with a bar of soap.
"STAY CLASSY, PAT!" the NRA video said in all-caps letters, before urging NRA supporters on Twitter to "let him know how you feel" with the hashtag #DesperateDavis.
Many tweeted profane messages of their own at Davis, a review of the hashtag showed.
An NRA representative did not immediately respond to a request for additional comment.
Davis, an Albuquerque city council member and former police officer, is one of six Democratic candidates running in the primary election for New Mexico's 1st congressional district. The winner of the primary election in June will face off against the Republican candidate in November. The incumbent, Democrat Michelle Lujan Grisham, is running for governor of New Mexico rather than seeking re-election for her congressional seat.
Davis told the Washington Post he wanted to address the issue of gun-control legislation during the primary race. He supports universal background checks and a return to a ban on assault-style weapons.
"I was a cop during the first assault-weapons ban and I'm telling you on the street it made a difference," said Davis, who was a police officer in Washington from 2000 to 2004, then in Albuquerque from 2005 to 2009. "This is the first election where it looks like we have as many mums and students and [gun-violence] survivors as the NRA has members. I don't remember another year like that where this [issue] was sustaining long enough."
The idea for the campaign ad was born out of frustration with the status quo, he said.
"Every idea we came up with looked like every other gun ad we'd ever seen," Davis said. "Finally, somebody just said, you know, like, [bleep] the NRA. We've told stories and everybody's marching and another ad of stock footage of that is not going to change the game. Everybody's thinking it. Why don't we just say it?"
The ad was filmed in a single day against the Sandia Mountains in Albuquerque. The campaign spent about US$250 to buy only one lunchtime spot on KRQE News because they weren't even sure if the station would run it, Davis said.
KRQE general manager Bill Anderson said in a statement that federal election laws required the station to run Davis' ad uncensored. He also said it had preceded the commercial with a 15-second warning about offensive language.
Since the ad aired, Davis said he had been inundated with "belligerent, vulgar" messages from NRA supporters, as well as donations and messages from people who encouraged him to continue in that vein. Among the latter was David Hogg, a student who survived the February 14 mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida.
Hogg has been one of the most vocal teenage activists to emerge from the Parkland tragedy, speaking at the March for Our Lives rally against gun violence in Washington. Since the shooting, he has appeared frequently on television and rallied his growing number of Twitter followers to become civically engaged.
Davis said his campaign did not know Hogg and was "totally surprised to have David pay attention and see it and share it."
Debates about the appropriate use - and broadcast - of profanity have become prominent in recent months, particularly concerning several high profile (and profane) incidents involving President Donald Trump. In January, when Trump referred to African countries and Haiti as "s***hole countries," most newspapers and TV stations didn't censor the President's vulgar language.
Davis brushed off criticism that his ad was inappropriate or that it contributed to the coarsening of public political discourse.
"Being polite for years has just given us thoughts and prayers, but this clearly got their attention," Davis said. His main objective, he said, was to "start a conversation" about gun-violence prevention.
"Our primary in just three weeks is one of the earliest in the country," he added. "If we can show that Democrats can stand up and run on this as a front-running issue, other Democrats with other challenges down the road will follow our lead."
One of Davis' Democratic opponents, Debra Haaland, indicated she agreed with the ad's sentiments in the commercial but not with the tone.
"The NRA and the arms industry are responsible for horrific preventable deaths all across America - with communities of colour hardest hit by this epidemic of violence," Haaland told KRQE News. "I fully understand the anger many people are expressing, and I share it - even if I might use different words."
