Transcript for Unfounded 'QAnon' conspiracy theory gains traction in politics: Part 1
footprint into the real world. Here is "Nightline" co-anchor, juju Chang. Reporter: Boston, Massachusetts, a rally protesting the flu vaccine mandate. But here it is, a Q symbol. Greeting the president at the airport. And here at a blue lives matter rally in Brooklyn. Q is everybody. It's a movement. Reporter: A wild, conspiracy-based movement known as qanon. They first appeared at trump rallies in 2018. Tomorrow the headlines will be massive protests. Reporter: Their profile growing over the last two years. Culminating with this moment in the white house two weeks ago. The president being asked directly inside the briefing Thank you very much. Reporter: About those qanon The crux of the theory is this belief that you are secretly saving the world from this satanic cult of pedophiles and cannibals. Does that sound like something you are behind? I haven't heard that, but is that supposed to be a bad thing or a good thing? I mean, you know, if I can help save the world from problems, I'm willing to do it. Reporter: The letter Q may be one of the least-used letters in the English language. But for followers of q-anon, it's a doorway into something called the deep state, a baseless idea that claims a secret, powerful network is working to promote its own hidden evil agenda and that Donald Trump is doing all can he to stop them. The movement leaping to headlines in the news. It's called q-anon, a fringe conspiracy theory. Qanon's grown so fast. Reporter: And it's caught fire with followers all over the nation, inspiring a few to take dangerous actions. With cops are after mow. Reporter: Uploaded on social media, leading them to be charged with major crimes. It's also attracting would-be politicians. Q is a patriot. He is someone who is very much, loves his country. Reporter: Marjorie Greene received a congratulatory tweet from the president. The broad narrative is that the world is controlled by satan-worshipping pedophiles, and they control everything, including the media and entertainment and politicians. Reporter: He has been tracking the group and hosts his own podcast, called the q-anon anonymous podcast. There's nothing wrong believing crazy things, there's conspiracy theories about big foot and area 51. The problem is these people are being radicalized in the sense that it becomes a major part of their life. Reporter: Followers believe Q is an actual figure or figures within the U.S. Government, holding q-level security clearance. Q is a real clearance level within the energy department, but from there, the story leaps into dark and outlandish places. For example, they say Q communicates with them by posting cryptic ciphers online because he has access to the deepest darkest secrets in the U.S. And wants to expose them. This includes wide, fake theories of prominent politicians running a child sex trafficking ring or that JFK Jr. Was assassinated by Hillary Clinton. But a right wing watch group claims these claims have now begun impacting reality. What the movement does is take that grain of truth, work it and twist it into their existing world vow and narratives. It's a movement that has wrin spired some of its followers to commit egregious criminal actions. So trump's statements about q-anon speaking favorably of them, I fear as having watched this for so long is incredibly dangerous. Reporter: Qanon's debunked theories have gained so much traction that Twitter and Facebook have been forced to take action, removing thousands of accounts off their platforms. Though a recent analysis alleges some are trying to reform pages under code names. Give us a sense of how popular you think is now. It's very difficult. There's really no reliable poll about the size of the qanon community. There's a presence in 71 countries. In a memo, the FBI described the group as a potential domestic terror threat, citing several acts of violence linked to followers, including when an armed man in an armored vehicle blocked a highway near the Hoover dam. He eventually pled guilty to terrorism charges. Do I think they're starting to cross a line? Their ideology and rhetoric are becoming more violent. Reporter: Eric Jackson is a former FBI agent who specialized in terrorism. There's a form of terrorism that I think is broadly referred to as lone-wolf terrorism, right? Is qanon that type of inspiration potentially? I think they are. What makes that individual difficult and where qanon may be a foundation for those type of individuals, they're operating beneath the radar. They're using a social media to gather the ideology. Reporter: Most recently, some people who appear to be Q followers have taken matters no their own hands. If you drul believe they are doing these satanic, evil things. On June 9th, this video was posted to his Facebook. Once the facts are out, that was just a theory that's a fact. Reporter: Two days later. I'm not driving like a mad man. Reporter: He gathered his children into a vehicle, allegedly throwing their mother out of the car after convinced she was trafficking their children and sparking an hour-long chase with police which he live streamed on Facebook. Come and get us! Reporter: He calls out, asking president trump for help. Donald Trump, I need a miracle or something. Somebody cue in and help me. Reporter: He was eventually stopped, arrested and charged with three counts of felony reckless conduct. It's a dramatic escalation for a movement that first found its footing four years ago in 2016, stemming from the absurd and false story known as pizza-gate, when this Washington, D.C. Pizza parlor became part of a conspiracy saying that the Clintons were running a trafficking ring. It's a lot of the founding ideas that qanon has built on can be traced back to pizza-gate. Qanon came along and built a, you know, kind of pizza-gate on steroids. Reporter: The theory then found a home on 4chan in 2017, spreading like wildfire who anticipated predictions, suches a the one that predicted Hillary Clinton's eminent arrest. They developed a lot of excuses as to why Q's predictions always failed. They say for example misinformation is necessary. They think Q is trying to trick this global cabal. It involves the whole space force, possible alien life, like pedophiles, and it seeks to tie all that together. Reporter: We first met Melissa Dietrich at this trump rally in August 2018. Melissa has voted for Obama in the past. But at the time they dabbled in the early stages of qanon, building a following of 20,000 on social media. They're cryptic messages that require a certain level of a lot of times we rely on people we call the anons. If you believe like we do, we think humanity is at stake here. Reporter: Now the movement has manifested into our nation's green, that GOP candidate for congress from Georgia posted this video about Q in 2017. And he's on the same page as us. And he is very pro-trump. Reporter: Green reversed her pro-q stance last month saying once she started finding misinformation she decided she would choose another path. This should be the of make California great again. Reporter: But a few congressional candidates still give qanon credibility. He is fighting an uphill battle for a congressional seat. Do you believe in this conspiracy theory that there is a satan-worshipping global cabal who are pedophiles and that that is somehow covered up fwhi deep state? So I give the allegation credibility. I don't know if this is true or not. I feel my responsibility as a congressional candidate is to know everything. What's on the horizon, what are people thinking? I started checking into it, and a lot of it, I agreed with. And there are some fringe elements I don't agree with. Reporter: Do you ever feel it's irresponsible to support qanon's conspiracy theories? Everything you said there is not true. There is evidence to the contrary that some of these things alleged are true. And I would say what's really intriguing to me is -- Reporter: I guess just because sex trafficking is real doesn't mean the conspiracy theory around it is. Well, I think there's plenty of evidence out there. I keep getting sent heinous videos all the time of children being trafficked. Reporter: The difference is not that child sex trafficking doesn't exist, but that there is a a deep state conspiracy that is trafficking in these young children. I don't have a doubt in my mind that this exists, and I would say that those who deny it exists, prove mow wrong then, if I'm right and the Q crowd is right about this, then I'm so thankful that they're shedding light on this. At this time. And that, if that's the great awakening, then so be it. Reporter: For a movement built around trump as a savior-figure. The president's refusal to publy disavow the group seems to be a rallying cry. When he makes little statements, little overtures, little retweets that seem to affirm something, I believe it.
This transcript has been automatically generated and may not be 100% accurate.