March, 2 2016: This story has been corrected and updated.
In the final two weeks before Super Tuesday, Republican super PACs coalesced, airing roughly 8,500 ads blasting GOP front-runner Donald Trump, according to a Center for Public Integrity review of new data provided by Kantar Media/CMAG.
The ad blitz, however, may be too little, too late. Trump’s Republican rivals have been slow to attack him and only recently have singled him out on the airwaves.
“I don’t think [Republicans] saw him as a true threat,” said Travis Ridout, co-director of the Wesleyan Media Project, which tracks political advertising. “He breaks the mold of what we’ve seen in the past 50 years.”
Super Tuesday’s GOP nominating contests in 12 states came after a three-state winning streak for Trump. His streak continued when he won in seven states and added an expected 234 delegates to his grand total. Trump’s success heightens anxiety among the Republican establishment wing that once doubted his ascendance.
“People are starting to panic,” said Johanna Dunaway, a political science professor at Texas A&M University. “So now, you see the efforts to try to stop his path to nomination.”
This spending frenzy will likely persist, especially after the real estate mogul’s Super Tuesday haul.
Following last night’s results, Ridout said it’s too soon to say if the ads slowed Trump’s momentum, though he said he is noticing more criticism of Trump.
“In order to successfully take him down, you need a coherent counter narrative — a way to define him other than the way he’s defined himself,” Ridout said.
The week going into Super Tuesday, 64 percent of negative or so-called contrast ads were anti-Trump. Conservative Solutions PAC — a super PAC supporting Sen. Marco Rubio of Florida — waged a $4.5 million anti-Trump campaign in just the past week, according to federal campaign finance filings.
Ahead of Super Tuesday, Conservative Solutions PAC saturated the TV airwaves, launched digital ads and even turned to the mobile messaging application Snapchat.
At a rally in Georgia on Saturday, attendees could use a Snapchat “geofilter”— location-based images that overlay photos or video — to don a virtual red cap similar to Trump’s signature “Make America Great Again” hat, which was instead emblazoned with the words “Stop the Con Artist.”
Conservative Solutions PAC reserved more than 4,500 spots that hounded Trump during the past week, according to Kantar Media/CMAG data. One ad titled “Know Nothing” slams Trump for not immediately disavowing the endorsement of David Duke, former leader of the Ku Klux Klan.
Katie Packer, a former Mitt Romney campaign staffer, established a super PAC solely dedicated to discrediting Trump. Formed days before the Feb. 1 Iowa caucuses, Our Principles PAC has spent about $4.4 million on anti-Trump ad barrages that cast him as a liberal.
For Super Tuesday, it aired anti-Trump spots nine times nationally, spending just over $400,000.
Also targeting Trump is Club for Growth and American Future Fund — two conservative outside groups that have spent millions of dollars in recent elections.
Club for Growth aired nearly 1,000 ads ahead of Super Tuesday.
Meanwhile, American Future Fund — a group with ties to conservative billionaires Charles and David Koch — released three ads this week featuring former Trump University students who say they were scammed and forced into debt by Trump’s educational endeavor, which is now facing lawsuits in New York and California.
“I was trumped by Trump,” said one ex-Trump University student over a melancholy piano tune. “I was duped by the Donald.”
Republican Sen. Ted Cruz of Texas and Stand for Truth — a super PAC supporting Cruz — took jabs at Trump as well. Together they aired hundreds of ads critical of Trump.
The anti-Trump ads do not come without retaliation. Trump assailed Super Tuesday states in the South with more than 3,000 ads since Feb. 22.
So will the sustained barrage of anti-Trump ads slow the candidate's momentum?
“A sustained coordinated effort could definitely knock him down a notch or two,” said Ridout of the Wesleyan Media Project. “Is that enough for someone else to come in to prevent him from a nomination? Perhaps.”
Michael Beckel contributed to this report.
This story was co-published with TIME.
Correction, March 2, 2016, 1:32 p.m.: An earlier version of this story reported that 6,000 anti-Trump ads were aired in the two weeks prior to Super Tuesday. Super PACs and candidates aired about 8,500 ads.