In podcasts recorded over the last several years, the Washington state Republican representative Matt Shea has amplified far-right conspiracy theories, stoked fears of civil war and speculated about the breakup of the United States.

Shea appeared as a guest in 2018 on the podcast Prepper Recon, hosted by “Christian constitutional author” Mark Goodwin, who writes apocalyptic survivalist fiction. Shea spoke on the podcast topic, “US civil war is coming”, and the “balkanization” of the United States.

At one point, Shea said “essentially we already live in two countries”. Asked by Goodwin if the two halves of America could continue to coexist, Shea said: “You know, I don’t think we can, and a lot of people would be kind of stunned maybe by that. I don’t think we can, again, because you have half that want to follow the Lord and righteousness and half that don’t, and I don’t know how that can stand.”

Shea predicted conservatives would hold out in “regions of freedom” like the American Redoubt, a geographical term for parts of the north-west US coined by another survivalist author, James Rawles, and the center of a rightwing “political migration” movement. In such regions, Shea said, people could “push back against the ever encroaching arm of the left, and more appropriately, the communists”.

Shea predicted that “more likely than not … some sort of Balkanization” was ahead, “because those regions of freedom are already forming right now”.

He added: “I think the right as Christian Patriots are ready at least in this area for what is about to happen.”

In his comments, Shea repeatedly stokes conspiracy theories with antisemitic overtones.

Republican lawmaker stokes fear of civil war and amplifies conspiracy theories in podcast - audio

Asked if groups like Latinx advocacy organization UnidosUS (formerly La Raza) were working together with protest groups like Antifa and Black Lives Matter, Shea claimed that these groups were also cooperating with other groups and were funded by the billionaire George Soros. “They are working together, it’s happening. They are very well connected through their networks, and their networks generally lead back to one George Soros, as you know,” he said.

Conspiracy theories about the influence of Soros – who is Jewish – have been disseminated broadly on the American right in recent years, despite the theories being widely denounced for reproducing antisemitic tropes.

Shea added: “If it could ever be proved that George Soros is arming the left in the United States, I think that would be enough to at least try to prosecute him”.

Shea did not respond to the Guardian’s requests for comment.

Shea then talked about two other far-right conspiracy theories.

Referring to a UN warning about racism in the USA after Charlottesville, Shea claimed that international genocide treaties “can actually allow the United Nations to deploy troops inside the United States of America if that treaty is invoked”.

I don’t think we can [coexist] because you have half that want to follow the Lord and righteousness and half that don’t

As for camps set up by the Federal Emergency Management Agency – which have long been held by the far right to be an infrastructure for detaining US citizens in concentration camp-like conditions – Shea said the National Shelter System “literally has a list of all the places people could be sheltered in and refugee camps created”, adding, “Could these then be used for nefarious purposes later? Sure!”

Conspiracy theories about Fema constructing facilities which would eventually serve as concentration camps for Americans were broadly held by members of the American militia movement in the 1990s.

The same is true of fears of a UN takeover of the United States, and the inception of a “New World Order”. More recently, these conspiracy theories have been partially mainstreamed by broadcasters like Alex Jones.

Shea’s own broadcasts on a Christian radio station are also released as a podcast, Patriot Radio. On this show, he has hosted a long string of far-right figures.

In October 2018, Shea hosted Alex Newman, a writer for the far-right John Birch Society’s New American magazine. Newman told Shea that “globalists” who constituted a “deep state behind the deep state” were orchestrating a “war on America … a war on humanity, a war on God”.

“We’re not just dealing with people we disagree with politically, we’re dealing with actual evil,” Newman added.

Shea offered that “a lot of people personify that evil with George Soros, you know, Dr Evil, he’s the guy. But there’s a lot more to it than that.”

Newman responded: “Soros is not the top of the pyramid … Soros got his start with Rothschild money.”

The Rothschild family have also long been staples of antisemitic conspiracy theory. The John Birch Society has consistently denied the charges of antisemitism which have dogged it since its heyday in the 1960s.

In April 2018, Shea hosted the conspiracy theorist Jerome Corsi to talk about the “deep state”. In August that year, he spoke to Robert Spencer, whose anti-Muslim views were heavily cited in the manifesto of the Norwegian mass killer Anders Breivik. The previous January, he spoke with “constitutional sheriff” Richard Mack, who has promoted ideas of “county supremacy”, which holds county sheriffs are the ultimate source of law in the US, not the federal government.

Shea’s most frequent podcast guest is Jack Robertson AKA John Jacob Schmidt, who in leaked chats with Shea spoke about violent fantasies about political opponents, as revealed in the Guardian.

In June 2018, Shea interviewed the Washington Republican house leader, JT Wilcox, who in recent weeks called parts of the leaked chats “wrong and deeply upsetting”, and promised an investigation into Shea’s involvement.

Shea’s leaked chats have been widely condemned. In a letter, House Democrats in Washington demanded Shea be stripped of his committee post and reprimanded. However, Wilcox responded that Shea was entitled to due process.