THE right-wing maverisk political consultant Roger Stone warrants at least a couple of mentions in books by senior US Democrats analysing the shock 2016 election defeat of Hilary Clinton by Donald Trump. They’re not what you would describe as complimentary.

Clinton herself describes Stone as a “such a bizarre character [that] it was hard to know how seriously to take anything he said”. Donna Brazile, former interim chair of the Democratic National Committee, goes further describing him thus: “That sleazy, leering, white-haired Nixon operative who was a big supporter of Donald Trump."

Stone, 65, is a notorious provocateur and the consummate Republican insider - and he is on his way to the UK for a speaking tour, so prepare for some shocking behaviour or comment, this is the man who infamously said, after all, that there would be an 'insurrection' if Trump was ever impeached. Stone was a bit-player in Watergate, was involved with George H. W. Bush’s successful campaign, was a regional political director with Ronald Reagan's 1980 campaign, worked on Bob Dole's unsuccessful run for the White House, had a role in the Florida recount of 2000, and is a long-time confidante of Donald Trump's. Small wonder that the journalist and author Jeffrey Toobin should say of him: "Roger is the sinister Forrest Gump of American politics. He's not just this simple-minded guy, but this Machiavellian, almost crazy guy who shows up at almost every key moment in recent American history."

Stone, who was kicked off Twitter last October for a series of characteristically incendiary tweets aimed at anchors and contributors on CNN, revels in the loathing that liberals have for him, and in his reputation as a master of the political dark arts. But it’s not just Democrats who are appalled by him. Ted Cruz, who fought unsuccessfully for the Republican presidential nomination in 2016, has spoken of Stone having “50 years of dirty tricks behind him” and that “his entire business has been dirty tricks, has been lies, has been personal smears.” Stone, however, has the hide of an elephant. The greater his notoriety, the happier he is. He seems to genuinely thrive on hate.

Stone left Trump's campaign in 2015 (he says he quit, the campaign insists he was fired, and genuinely no-one seems to know what is true and what isn't - he is the master of the dark arts after all) but he continues to take a close interest in the president's welfare. Responding earlier this week to Trump’s statement that he was “looking forward” to speaking under oath to Mueller - the former FBI director now investigating Russian meddling in the election - Stone told Fox News that it “would be a suicide mission” for the president to talk to Mueller. A “first-year law student” would advise Trump that Mueller was setting “an obvious perjury trap”, he added.

Stone, who on Tuesday will address the Oxford Union and on Wednesday speak to the UK's oldest conservative think-tank The Bow Group , is now said to be writing a book about Trump's downfall, entitled The Unmaking of the President. (He wrote a campaign book of his own, The Making of the President in 2016).

Last year Stone was the subject of the film Get Me Roger Stone, a remarkable Netflix documentary. “My name is Roger Stone and I’m an agent provocateur,” are his opening words to camera.

The documentary chronicles his early interest in Republican politics - he attended his first GOP convention, in 1964, at the age of 12. While a student he had a walk-on role in Richard Nixon’s dirty tricks campaign in the early 1970s. Stone claims he was the youngest person to appear in front of the Watergate grand jury. He later had Nixon's face tattooed on his back.

He chaired the Young Republicans and co-founded the National Conservative Political Action Committee, which helped drag the GOP in a more right-wing ideological direction and led to the use of negative campaign advertising. Stone played a role in helping Reagan beat Jimmy Carter, and it was during this campaign that he first encountered Trump.

With Reagan in the White House, Stone established Black Manafort and Stone (BMS), a political consulting and lobbying group with, amongst others, Paul Manafort, who in 2016 would replace Corey Lewandowski as Trump's campaign manager. Last October, Manafort surrendered to the FBI after being indicted by a federal grand jury as part of Mueller's investigation.

BMS offered their high-profile corporate clients a "superior understanding" of how Washington worked, and it made its principals a great deal of money. But it became known, to some critics, as the "torturers' lobby", for its willingness to do business with disreputable figures. In the documentary Jane Mayer, author of Dark Money: The Hidden History of the Billionaires Behind the Rise of the Radical Right, says: "When people think of Washington corruption they think of organisations like Black, Manafort & Stone, that shook down dictators, took all their money and then tried to take America's government and make them serve the dictators' interest." With a nod to Trump's 'drain the swamp mantra', she said of BMS: "You know, it is 'the swamp'."

Stone's reputation was permanently damaged in the 90s by a National Enquirer story alleging that he had run personal ads in a swingers' magazine. He said he had been set up by a "very sick individual," and was forced to quit Bob Dole's campaign. Many years later, he admitted that the ads had been genuine.

Stone was an early and enthusiastic supporter of the idea that his friend, Trump, should run for president. It took a long while for Trump to finally commit, but when he did, he upset all the odds to defeat Clinton. Jeffrey Toobin says: "In many respects, Roger Stone created Donald Trump as a political figure. There is no doubt that in tone, in affect, in profile, the Trump candidacy was a pure Roger Stone production."

Stone is a hero to Trump's base in America: they buy his books and adore him for his virulent attacks on the Clintons. He has been caught up in the Russia probe - he rejected allegations of collusion at the House intelligence committee last September - and has reportedly returned to lobbying. The Daily Beast said earlier this month that Stone "is advocating for military operations, including drone strikes, in Somalia on behalf of his first lobbying client in 17 years."