Since the rise of Donald Trump, there has been a mystery about how and why so many otherwise respectable, seemingly intelligent and well-informed, Republicans could embrace his preposterous fabrications. A new trove of emails reflecting top-level behind-the-scenes conversations at Fox News Channel, the highest-rated US public affairs network, illustrates in vivid and deeply disturbing detail the process that produces a deliberate embrace of falsehood over basic and objectively verifiable truth. Now we know. The lessons go far beyond Fox. It is an excellent road map of the process through which most Republican leaders refused to challenge the worst of these falsehoods, especially the "big lie" that the 2020 election was somehow "stolen" from Mr Trump. The cynicism and corrupted groupthink at Fox News has reflected in Congress and state houses around the country. It has left most of the US right detached from reality and beholden to a preposterous fairy tale that is highly damaging to the country and corrosive to democracy. The emails exposing the systematic dishonesty at Fox were obtained by Dominion Voting Systems, which makes the voting machines used in much of the country. Dominion is suing Fox for defamation because of the barrage of false accusations made by guests and hosts on the company’s flagship programmes. To this day, Fox's most significant shows —<i> Fox and Friends </i>in the morning and the evening primetime troika of Sean Hannity, Laura Ingram and Tucker Carlson — routinely promote a wide range of conspiracy theories, often targeting Dominion, purporting to explain that Mr Trump won the election. But what the company, which has probably become nonviable because of this crude defamation, has already achieved through its $1.6 billion lawsuit is: irrefutably establishing that the Fox hosts and officials knew perfectly well that such claims were ridiculous and privately disparaged many of the regular guests as lying. But at the same time, they insisted that the network must "respect" the audience by telling it what it wants to hear, rather than what the organisation knows full well to be true. That is much closer to disdain than respect. Hosts and guests on the network routinely claimed that Dominion was founded or controlled by Venezuela and Cuba, and that its machines could be "hacked" and "rigged" to "flip" vast numbers of votes from Mr Trump to US President Joe Biden. None of this is true, or even possible. In the White House, then-attorney general William Barr, among many other officials, strongly warned Mr Trump these claims were outlandish. He later testified that he worried that, because he seemed to take such interest in them, the former president was losing touch with reality. Even more significant, though, are the insights into why a self-described "news” network would base so much of its programming on incendiary untruths. The emails demonstrate that the Fox News anchors and executives were fixated on ratings (and thus advertising revenue), and virtually panicked when large chunks of the Trump-adoring fan base began turning against the channel after it correctly predicted Mr Biden's victory in Arizona. As Fox's ratings dropped and its tiny but even more extreme and Trump-obsessed competitors, Newsmax and One American News, rose, emails between the network’s stars and executives show they quickly concluded that their all-important audience was not interested in verifiable truth, but was actively seeking comforting, reassuring and reinforcing falsehoods, especially denying or at least casting doubt on the fact that Mr Biden soundly defeated Mr Trump. And they noted that the more they focused on conspiracy theories about the election, the more their audience returned to them. So, they decided to provide the audience with what they crave, no matter how absurd. It is the antithesis of news and a quintessence of propaganda. Moreover, the emails demonstrate that Fox News's movers and shakers were actually afraid of their audience. And undoubtedly the same calculation was obvious to Republican officials and candidates in Congress and state houses around the country. A few may be fanatical, conspiratorial or just plain gullible to believe such absurdities. How could Mr Biden wrongly and so many Republicans rightly be elected on the same ballots if they were fraudulent? Why would Democrats cheat to secure the White House but not give themselves a majority in the Senate? In the main, they appear to have followed the same logic about their voters as Fox officials did about their viewers. Some Republican<b> </b>voters believe the "stolen election" mythology because they heard it from Mr Trump, from Fox News and the others, and from their own elected officials (who, at the very least, did not try to disabuse them of this delusion). Mr Trump and his allies moved quickly to make election denial a litmus test to distinguish "real Republicans" from "Republicans in name only" (the detested "Rinos"). And they demonstrated during the midterm election that they can still decide most Republican primaries although, with a few scattered and rare exceptions, purveyors of the big lie lost in the general elections. Now it has become a self-reinforcing mythology of totemic proportions. At the weekend, Republican voters in Michigan — where Democrats secured complete control of the state for the first time in many decades in the midterms — doubled down on the outlandish by selecting Kristina Karamo, one of the US's most vociferous election deniers to be their state party leader. She defeated a slightly less enthusiastic election denier who was endorsed by Mr Trump and the party leadership. Allowing for scatterings of oddballs and conspiracy theorists, there is no doubt that Republican officials and leaders followed the same path into absolute dishonesty that the Dominion lawsuit email trove demonstrates Fox leaders did. Most alarming is the spread and casual acceptance of a complete fabrication. It is one of the surest signs of the emergence of authoritarian political systems whether of the left or the right. But the Fox email trove demonstrates exactly how and why the US political right has become a solar system guided by one gigantic lie and orbited by countless smaller ones. That's a catastrophe not only for the Republican Party, but for the whole country.