Demonstrators protest the visit of US President Donald Trump to the site of the mass shooting in Dayton, Ohio, on August 7, 2019.

Megan Jelinger | AFP | Getty Images

Gun control advocacy groups have dedicated more than $2 million on digital and TV ads, widely outspending the National Rifle Association, since the mass shootings weeks ago in California, Texas and Ohio that left more than 30 dead.

An organization mostly funded by Michael Bloomberg, the billionaire and former New York mayor, is leading the way with a $935,000 ad campaign calling on Congress to require tougher background checks for gun sales along with strong red flag laws, which are meant to take firearms away from those deemed a threat to themselves or others.

The NRA has spent just $14,000 on Facebook ads since last week. Instead, the group focused its recent advocacy on tweeting and being in direct contact with President Donald Trump.

Gun control advocates say the NRA may not spend as much for lobbying going forward because they have Trump’s ear.

“There is not a response from them to counter the overwhelming push from the American people, politicians and activists on this issue,” said Andrew Patrick, media director at the Coalition to Stop Gun Violence. “In the past, they get their lobbying going. Now they can call the president and he can prepare their talking points.”

The spate of shootings have given organizations calling for tighter gun laws new momentum in their push to change laws, particularly as big-money backers like Bloomberg look to counter the decades long influence the NRA has exerted on Capitol Hill.

Bloomberg’s Everytown for Gun Safety is planning to spend $1 million on digital and TV ads focusing largely on Republican senators who have resisted calls for tighter gun control. They include Senate Majority Leader Mitch McConnell, Marco Rubio, Rick Scott, Richard Burr and John Cornyn, with most of these lawmakers previously receiving NRA contributions. The ads will start airing next week and will continue through the August recess.

Shannon Watts, the founder of Moms Demand Action for Gun Sense in America, which is part of the Everytown group, says Senate lawmaker will have to listen or expect to face a tough re-election battles.

“We’re hopeful that the senate will act but if they don’t there will be hell to pay in 2020,” Watts told CNBC on Thursdeay. “We are having our events in all fifty states, and its really important that senators in red, blue and purple states listen to these constituents,” she added. Their organization is also spending $65,000 on these nationwide rallies that are scheduled to take places this weekend.

A Fox News poll taken between August 11-13 showed that 90 percent of participants support requiring all potential gun buyers to go through a criminal background check, while 81 percent said they’d like red flag laws.

Sandy Hook Promise, a nonprofit organization that was created by the families of victims of a 2012 gun massacre that took place at an elementary school in Connecticut, has spent just over $300,000 on Facebook ads since Aug. 7, according to the company’s ad library. The most recent ad shows a boy named Dylan, who was killed during the mass shooting nearly seven years ago, and calls on Congress to limit the size of gun magazines.

Only billionaire and presidential candidate Tom Steyer, who has spent over $900,000 over the past seven days, has spent more than Sandy Hook Promise on Facebook ads.

Ban Assault Weapons NOW, a nonprofit whose leadership includes survivors of various mass shootings, has spent just over $90,000 on ads since this summer’s mass shootings. Its latest message calls for people to sign their petition urging a ban on assault weapons in Florida. It also criticizes Congress for its inaction on gun laws and its members ties to the NRA.

A gun control advocacy group founded by former Arizona Rep. Gabrielle Giffords has launched a $750,000 TV ad campaign that will call for McConnell and Sen. Cory Gardner to support background check legislation.

While the NRA hasn’t spent much recently, it used other means to gets its message across, however.

On Twitter this week, the NRA posted an ad featuring CEO Wayne LaPierre, who describes “a highly orchestrated effort to disarm American citizens unlike anything we’ve ever seen in this country.” As he speaks, the ad shows video of Democrats running for president, including Joe Biden, Elizabeth Warren, Kamala Harris and Beto O’Rourke.

That same ad has been retweeted by various pro-Trump voices, such as former White House official Sebastian Gorka, and Tomi Lahren, a Fox News personality who regularly backs the president.

The NRA vehemently opposes universal background checks, and, months before the recent slate of mass shootings, spent $1.6 million lobbying against legislation that would implement those very same principles.

The NRA, which spent $30 million in support of Trump’s 2016 campaign, also has a direct line to the president. Trump has said he’s spoken with LaPierre and suggested that the organization will be neutral in the gun debate this time around.

“I think in the end, Wayne and the NRA will either be there or either be a little more neutral,” Trump said at the time.

A spokesperson for the NRA did not return a request for comment.