London: For a while, the campaign to find a successor for blond faux-buffoon Boris Johnson as London mayor looked to be one of the duller events of a busy political spring.
Elsewhere the Conservative Party was tearing itself apart over Brexit, while Labour tore itself apart over Jeremy Corbyn's ongoing leftpocalypse.
Meanwhile in London an affable, rather toffy Zac Goldsmith, for the Tories, looked likely to lose London to Labour's Sadiq Khan, about whom the most interesting thing you could say was that he was the son of a bus driver, but unfortunately he kept saying it himself, to the point that months before this week's election everyone was sick of being told about his dad the bus driver.
Then, suddenly, the campaign lurched into the gutter.
Labour suddenly tipped into a fresh crisis over alleged anti-Semitism in its ranks. The Conservative campaign team, watching their former frontrunner drift behind in the polls, happened to be feeling desperate. Sadiq Khan happens to be Muslim.
So they put two and two together and got Islamic State.
"Are we really going to hand the world's greatest city to a Labour Party that thinks terrorists are its friends?" said the headline on Goldsmith's comment piece in a Daily Mail article on the weekend.
It was a provocative summary of an article that warned: "If [Khan] wins we will have handed control of the Met [London's Metropolitan Police] … to a party whose candidate and current leadership have, whether intentionally or not, repeatedly legitimised those with extremist views."
It was a new dip in tone from a campaign that had already taken a modern Conservative – the environmentalist, principled son-of-a-billionaire MP for Richmond, former editor of The Ecologist magazine – and moulded him into a shameless political opportunist.
Conservative columnist Peter Oborne – former chief political commentator for London's Daily Telegraph – wrote that Goldsmith's campaign has "concentrated on Khan's religion, alleging that Khan is a friend and apologist for extremists and therefore cannot be trusted.
"These claims are absurd. Khan is a mainstream Labour politician who has dedicated his career to advocating centrist views. He voted for same-sex marriage, thus estranging socially conservative elements in London's Muslim communities. He loudly opposes a boycott of Israeli goods. He is a strong opponent of anti-Semitism. He has campaigned constantly against reactionary and so-called 'extremist' forces within the Muslim communities.
"None of this is good enough for Goldsmith's Tory campaign, which has pumped out a constant barrage of propaganda portraying Khan as the pawn of sinister Islamist forces."
At his campaign launch, Goldsmith said Khan would be soft on crime because he "provided cover for extremists". Goldsmith's team sent leaflets to Hindu and Sikh communities in London claiming Khan supported a "wealth tax on family jewellery" - a tactic some described as racist, and even some supporters thought was stereotypical and patronising.
Such tactics have lost him the support of some moderate Conservatives. Conservative peer Baroness Warsi wrote on Twitter: "If Sadiq Khan isn't an acceptable enough Muslim to stand for London mayor, which Muslim is?"
If @SadiqKhan isn't an acceptable enough Muslim 2 stand for London mayor, which Muslim is? Imp piece by @mehdirhasan https://t.co/31VA0EbXWD— Sayeeda Warsi (@SayeedaWarsi) March 1, 2016
But others doubled down on Goldsmith's tactics. Boris Johnson lent help to his successor, saying Khan had "shared platforms ... with some pretty dodgy people with some pretty repellent views".
Home Secretary Theresa May said Khan was an "unsafe" choice at a time of "significant threat of terrorism". Defence Secretary Michael Fallon said Khan was a "Labour lackey who speaks alongside extremists".
Prime Minister David Cameron used parliamentary privilege to detail Khan's nine appearances alongside Sulaiman Ghani, who he said was a supporter of IS.
Ghani challenged the PM to repeat the "absurd and flagrantly flawed assertions" outside parliament, or else "apologise and retract his comments as a matter of urgency", saying he had "consistently like all mainstream Islamic scholars not only spoken out but condemned IS/Daesh for the monstrosity that they are".
Ghani also pointed out to the BBC that he had previously been invited by a Conservative candidate in Tooting to attend a meeting "to encourage more Muslims to become Conservative councillors".
Indeed, Goldsmith himself had also met Ghani.
Goldsmith's campaign has been advised by CTF Partners, the political consulting firm of Aussie campaign guru Sir Lynton Crosby, who coincidentally is off to Buckingham Palace on Friday to be officially invested in his knighthood for services to politics.
But the 'wizard of Oz' is unlikely to mention the Goldsmith effort to Her Majesty. According to the Financial Times' Sebastian Payne, "in private senior Tories feel the need to apologise for the Goldsmith campaign and they express regret at how it has been fought.
"Blame for the lacklustre campaign is being directed at [CTF] … some Tories thought they were buying the election-winning machine that delivered them a national majority last May."
But in fact Crosby has not been involved in the campaign to any significant degree, according to press reports – he never attended any Goldsmith campaign meeting or had any strategy role, with his colleague Mark Fullbrook masterminding the campaign instead.
It's a matter of conjecture whether Crosby would have blown his dog whistle with more subtlety, at least.
Khan, however, has not covered himself with glory during the campaign either. His progressive Labour credentials appear sound and very London: brought up on a council estate, he has spoken out against racism on football terraces, saying hooligans targeted him at a 1987 Tottenham Hotspur game because they thought he was Jewish. Gordon Brown made him the first Muslim to attend cabinet – as transport minister (a chance yet again to trot out the bus driver dad story).
But his work as a human rights campaigner gave the Conservatives ample ammunition for claims he had supported the wrong sort of people: such as Londoner Babar Ahmed, who was convicted for running a pro-jihadist website (again, awkwardly for the Conservatives, Goldsmith had also expressed support for Ahmed).
And on the eve of the election, the press unearthed a 2009 interview with Iran's state-backed Press TV, when Khan was minister for community cohesion, in which he dismissed moderate Muslim groups as "Uncle Toms". In context, he was discussing how he had consulted widely in the Muslim community in the cause of community cohesion, but the choice of words was poor – and played to the Conservatives' line.
Polling has Khan running a very strong favourite to be London's first Muslim mayor.
Polling in Britain has a recent history of being wrong, but even if it's right, the man who talks of a cosmopolitan, diverse city inherits a London on edge after a racially charged campaign.
