In recent days, many on the right have pushed the claim that the FBI “infiltrated” President Donald Trump’s 2016 campaign with a “mole.” The claim relies upon the testimony of a co-founder of Fusion GPS, the research firm that hired a former British agent who compiled an intelligence dossier about Trump’s connections to various Russians. The claim also builds off of a recent squabble between the Department of Justice and the chairman of the House intelligence committee, Rep. Devin Nunes (R-CA), over the release of classified information. Here is what you need to know about the story’s origins:

• On January 2, Glenn Simpson and Peter Fritsch, the founders of the research firm Fusion GPS, claimed in an op-ed that the FBI had a source “inside the Trump camp” during the 2016 election.

• On January 9, the transcript from Simpson’s August 2017 Senate testimony was released, revealing that he had told the Senate Judiciary Committee it was his “understanding” that the bureau had an “internal Trump campaign source.” Simpson also testified during the hearing that conversations he had with the author of the dossier about Trump’s Russia connections, Christopher Steele, led him to believe that the FBI had “a human source from inside the Trump organization.”

• The same day, reporters tweeted that the Trump campaign insider Simpson referred to was George Papadopoulos, a foreign policy adviser to the campaign, and that the FBI's source was an Australian diplomat who informed U.S. officials that Papadopoulos had mentioned to him receiving Russian dirt on Hillary Clinton in May 2016.

• Between January 9 and January 10, both The New York Times and The Washington Post reported that the “human source” Simpson had mentioned was allegedly the Australian diplomat, Alexander Downer.

• On January 18, however, a lawyer for Simpson sent a letter to Senate Judiciary Committee Chairman Chuck Grassley (R-IA) asserting that Simpson “stands by his testimony.” The lawyer stated that Simpson was not withdrawing his claim that Steele had “believed the FBI had another source within the Trump organization/campaign.”

• On May 8, The Washington Post reported that the DOJ was refusing to hand over information requested by Nunes because it could “endanger a top-secret intelligence source.” The source, according to the Post, had developed information that was “provided to the Mueller investigation.”

• Two days later, The Wall Street Journal’s Kim Strassel published an op-ed in which she speculated that the FBI may have secretly had a source “who used his or her non-FBI credentials” to interact with the Trump campaign.

  • Strassel wrote in the Journal that the DOJ and the FBI “outright hid critical information from a congressional investigation," which could mean that the FBI had a spy linked to the Trump campaign.
  • Strassel wrote that “When government agencies refer to sources, they mean people who appear to be average citizens but use their profession or contacts to spy for the agency,” asserting that the FBI could have secretly planted a source who interacted with the Trump campaign.
  • ​According to Strassel, any such move on the FBI’s part would “amount to spying.”
  • Strassel also concluded that “Now we find [the FBI] may have also been rolling out human intelligence, John Le Carré style, to infiltrate the Trump campaign.”

• Strassel doubled down on her assertion during a May 11 appearance on Fox News, claiming, “The FBI was using human intelligence to spy on a presidential campaign.”

Right-wing media is pushing the “spy” theory 

Radio host Rush Limbaugh claimed he knows “who the spy is” and that this person was “like an operative employed by the FBI to basically entrap somebody who worked with the Trump campaign in a peripheral way.” He also said that Papadopoulos “was entrapped by three people, including the person who is reputed to be the spy."

Fox’s Sean Hannity argued that there was a spy embedded in the campaign and called the Strassel op-ed a “stunning new development” that raises “serious concerns and questions about the possibility [of] the F.B.I. planting a mole inside the Trump campaign.”

The hosts of Fox & Friends devoted multiple segments to Strassel’s op-ed and also highlighted Limbaugh’s theory that the FBI planted a “spy” to “entrap” Trump associates. Fox’s Pete Hegseth argued that Limbaugh is “on to something,” and co-host Steve Doocy asked, “Was the FBI out to frame candidate Donald Trump?”  

Trump sycophant and Fox Business host Lou Dobbs tweeted: “#ExposeTheMole- FBI & DOJ planted an spy in @realDonaldTrump’s 2016 campaign & didn’t tell congressional investigators.”

During an appearance on Hannity’s radio show, Fox’s Sara Carter claimed, “It appears [the FBI] had somebody that was reporting back on information inside the Trump campaign, which would mean that they had a mole connected to people in the Trump campaign or within the Trump campaign.” Carter repeated the report on Hannity’s prime-time Fox News show, claiming, “Yes, I believe [the FBI] did have an informant, somebody that was reporting back to them.”

The Daily Caller pushed the narrative in an article about Rep. Ron DeSantis’ (R-FL) appearance on Fox News: “Ron DeSantis Says He May Know Who Was Spying On The Trump Campaign: ‘There Needs To Be Follow Up’.”

Pro-Trump site The Gateway Pundit ran multiple articles by founder Jim Hoft that pushed the claim, including one in which Hoft claimed to know the “probable” identity of the “spy,” and another that argued there were multiple “deep state” sources.   

Far-right fringe blog Zero Hedge posted Strassel’s op-ed with the headline, “WSJ: The FBI Hid A Mole In The Trump Campaign,” even though Strassel never claimed the “mole” was actually inside the campaign.