The list of senior Tories slated to replace Theresa May when she is finally ousted from Number 10 Downing Street is getting shorter every week. Phillip Hammond’s reputation is cratering faster than the British economy; Boris Johnson is an obvious dud; and the appeal of staunch Brexiteers such as David Davis and Jacob Rees-Mogg is limited to the narrow confines of the Tory grassroots. But another name routinely cited in the UK media as a plausible alternative to May is that of Ruth Davidson, the Tory leader in Scotland.

You can see why some people think Davidson would be a smart choice. In addition to being young and media savvy, she can lay claim to something increasingly rare in modern Tory politics: actual, sustained electoral success. In 2016, the Tories dislodged Labour as Scotland’s second largest party at Holyrood and, at the general election in June, they won 13 Scottish seats, their best showing north of the border since 1983.

Davidson’s jaunty, unpretentious style, her image as a Cameronian moderniser, and her vocal support for the EU* have earned masses of praise from the centrist commentariat. “Said it a couple of years ago. Even more relevant now. Ruth Davidson is the Labour party’s worst nightmare,” The Daily Mail’s Dan Hodges tweeted during the Tory conference in October. “Where May is jumpy in public, Davidson is charming and at ease with the voters. She is a Martini politician,” the New Statesman’s Chris Deerin gushed over the summer.

But here’s the problem: Davidson’s glossy moderate image is a total sham. She is, in reality, a profoundly cynical rightwing politician, whose willingness to exploit and amplify some of the worst chauvinistic instincts of the Scottish electorate should permanently disqualify her from prime ministerial office. If you think this sounds hyperbolic, consider the astonishing growth of racist, anti-immigrant, and anti-Irish sentiment that has taken place within the Scottish Conservatives under her watch.

The charge sheet from last year alone is striking. At the local council elections in May, the Scottish Tories elected a slew of candidates who either had a track-record of making racist remarks on social media or who had links to far-right groups such as Britain First, the BNP, and the English Defence League; then Davidson reinstated two councillors in Stirling who had been suspended for using racial and sectarian insults online (one has since resigned); and shortly after that, the MP for Moray, Douglas Ross, told an interviewer that if he ever became prime minister, his chief priority would be to impose “tougher enforcement against Gypsies and travellers.” (In response, not only did Davidson refuse to reprimand Ross, she actively defended him, saying that he had highlighted “significant issues” for his constituency.)

These incidents follow a pattern of dog-whistle gestures by the Scottish Tory leadership. For instance, after a closely fought Old Firm match in 2016, Murdo Fraser tweeted, “Rangers 5 Celtic 4 – The Queen’s 11 deliver Her Majesty the perfect Birthday present.” Likewise, Davidson herself served for a while in the Territorial Army still constantly refers to and emphasises her military links.

For anyone even slightly familiar with the iconography of unionism in Northern Ireland, which fetishises the royal family and the UK armed forces, the messaging was and is unmistakable. Indeed, the Scottish Tories have a much closer relationship to the Orange Order than they are willing to admit. According to a report last year, which quoted Grand Orange Lodge of Scotland Grand Master Jim McHarg, a “huge number” of the Lodge’s estimated 50,000 Scottish supporters are Tories, and more members of the Order are now serving as elected officials across Scotland than at any time in the past two decades.

There have always been extreme elements on the Scottish right†. As a political tradition, it is defined by a drooling loyalty to antique British institutions, from the Crown and the Union to the empire and the military. But they are more pronounced now than they have been for years – and Davidson is directly to blame for that.

In an effort to shore-up opposition to independence, and to consolidate her electoral base, she elevated hardline unionism to the centre of her entire political strategy, relentlessly exaggerating the threat of a second independence referendum while simultaneously decrying the “turmoil and division” of the first one. The result was a form of turbocharged British identity politics, heavily laden with rightwing jingoism, that has resonated with some of the most backward and reactionary (and Orange-inflected) sections of Scottish society. That’s why she won’t publicly disown those members of her party who use arcane slurs to describe Irish Catholics, or who openly celebrate the sectarian lineage of Rangers Football Club, or who eulogise Enoch Powell. Her success is symbiotically linked to their support, and without them, she would be lost.

Of course, being belligerently patriotic isn’t exactly a disadvantage if you want to become prime minister (which, for the time being anyway, Davidson still disingenuously insists that she doesn’t). But that’s not the point. The Scottish Tory leader has repeatedly demonstrated that she is happy to pander to xenophobes and racists in order to boost her own short-term political interests.

The effects of this have been bad enough in Scotland, where the right remains, relatively speaking, quite weak. Picture it in the ideological tinderbox of Brexit England, however, and you begin to get an idea of how potentially combustive a Davidson premiership could be. Far from reintroducing a veneer of centrist stability to the Tory party, the government, and the country, Ruth Davidson would drag us all much deeper into a rightwing ditch if she thought she might get something – anything – out of it.

* Davidson’s liberal admirers should take note of her vacillations over Brexit. Shortly after the 2016 referendum, she stated unequivocally that she backed single market membership: “I want to stay in the single market,” she told the BBC, “even if a consequence of that is maintaining free movement of labour.” But she dropped this demand from a list of Brexit ‘tests’ she issued to the SNP a few months later. And, of course, she has completely failed to use whatever political clout she has to nudge May towards a less dogmatic position regarding the single market.

† Who funds the Scottish right? As Adam Ramsay and Peter Geoghegan revealed last year, the source of a controversial £425,000 Brexit campaign donation to the DUP was a Glasgow-based businessman called Richard Cook. As well as being a former vice chair of the Scottish Conservatives, Cook was once a spokesman for a pro-Apartheid lobbying outfit, the ‘Campaign Against Political Correctness’. Cook’s role in orchestrating the DUP donation illustrates how easy it is for Scottish Tories to access the vast resources of their elite – and often intensely secretive – backers. In April 2016, the ‘Irvine Unionist Club’ gave the North Ayrshire Conservative and Unionist Association £100,000. The group never appeared on the UK Electoral Commission’s official list of registered political donors and has since disbanded.