As Peter Dutton tells it, he has never given a damn about being popular.

"You don't have to be liked in politics," he said in April, explaining his leadership philosophy to radio broadcaster Neil Mitchell. "I've never seen politics as a Big Brother episode or as a reality TV show.

"You need to make tough decisions and people respect you in the end, I think, for sticking by your beliefs and sticking by your convictions.

"And if you want to be a populist and want to try and please everyone, you'll end up doing nothing in politics and I think in the end those people don't survive."

On Tuesday he was proven right when 35 colleagues - almost half of the Liberal party room -supported him in a leadership spill against Malcolm Turnbull.

The combative former cop from Queensland now stands on the verge of being prime minister despite being unloved or unknown by an overwhelming majority of Australians.

Opinion polls have consistently found his support among the general public to be virtually undetectable.

In an April Essential poll, just three per cent of respondents said he was their preferred choice as Liberal leader, far behind Malcolm Turnbull (24 per cent), Julie Bishop (17 per cent), Tony Abbott (11 per cent) and the hypothetical "Someone Else" (14 per cent).

Among conservative voters his support wasn't much better: just 4 per cent of Coalition supporters named him as their chosen leader.

And, yet, here we are.

Like the candidate for school captain who is a hero among their classmates but a teacher's nightmare, Dutton has long had a bifurcated appeal.

From his earliest days in Parliament he has commanded respect among his parliamentary colleagues and been seen as destined for high office.

Almost a decade ago, former treasurer Peter Costello singled Dutton out as a future leader, saying he had a "very high opinion" of him.

"He is a good thinker," Costello said in 2009. "He's got a great touch with the electorate and good campaign skills, and a bit of toughness which I like."

As he described in his first speech in Parliament, Dutton, 47, came from a "typical small business, middle-class family" in Brisbane. From aged 12 he was working casual jobs - delivering papers, mowing lawns, working in a butcher's shop - and graduated high school from St Paul's Anglican School.

At age 18 he joined the Liberal Party, which he said reflected his belief in "individualism and reward for achievement". In a testament to his ambition, he ran for state Parliament two years later in a safe Labor seat and lost.

Dutton then worked as a Queensland police officer for nine years, mostly in the drug squad but also in the sex offenders unit.

His time as a police officer cultivated a Manichean world view he maintains to this day: good and evil, friends and enemies, black and white. Nothing in between.

"I have seen the best and the worst that society has to offer," he said in his first speech. "I have seen the wonderful, kind nature of people willing to offer any assistance to those in their worst hour, and I have seen the sickening behaviour displayed by people who, frankly, barely justify their existence in our sometimes over-tolerant society."

Dutton entered Parliament in 2001 by narrowly taking the seat of Dickson from star Labor recruit and former Democrats leader Cheryl Kernot. This earned him a reputation as a giant killer, and after just three years John Howard appointed him to the ministry.

Despite the popularity of Kevin Rudd, Dutton held on to his seat at the 2007 election. On the first day of Parliament in 2008 he was famously one of a handful of Liberal MPs who boycotted the apology to the Stolen Generations.

He defended his decision by saying the apology would not deliver "tangible outcomes to kids who are being raped and tortured in communities in the 21st century". More recently he said he had underestimated the symbolic importance of the event.

In 2009 it looked like Dutton's career may be over when, after a redistribution made his seat notionally Labor, he made a botched attempt to shift to the nearby electorate of McPherson. Preselectors there rejected him, and he retreated to Dickson.

Dutton spent most of the Rudd-Gillard years as shadow health minister and kept that portfolio when the Coalition took power in 2013. His efforts to convince the public of the merits of a new $7 GP fee - a centrepiece of the 2014 budget - proved spectacularly unsuccessful and antagonised the powerful Australian Medical Association.

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A poll of doctors later found him to be the worst health minister in living memory.

At the end of 2014 Abbott shifted him to the immigration portfolio, a better fit for his aggressive style.

As minister, Dutton has pursued a play-to-the-base media strategy focussed on conservative-friendly outlets. He has matey weekly chats with 2GB host Ray Hadley and doles out stories to News Corp tabloids The Daily Telegraph and Courier-Mail. Meanwhile, he has accused Fairfax Media of waging "jihad" against the government and attacked the "crazy lefties" at the ABC and The Guardian for focussing on allegations of mistreatment of asylum seekers on Manus Island and Nauru.

He has made gaffes, like when a boom microphone captured him making jokes about the plight of Pacific Island nations facing rising sea levels. And when he accidentally texted a female journalist calling her a "mad f-cking witch".

He has become the government's chief attack dog in question time, taking obvious relish in going after Opposition Leader Bill Shorten for the "inherent weakness" in his character and his links to "thugs" in the construction union.

At the height of the Barnaby Joyce affair earlier this year, Dutton attacked his political rival in an unusually personal way by pointing to "a history of problems" in Shorten's private life.

Dutton supported Tony Abbott in the 2015 leadership contest with Malcolm Turnbull, but soon formed a close and productive working relationship with his more progressive colleague from Point Piper.

Faced with increasingly public undermining by Abbott, Dutton and his friend Mathias Cormann have been crucial in maintaining Turnbull's support among conservative MPs.

Dutton and Cormann were the architects of last year's postal survey on same-sex marriage, devised as a way to alleviate a political headache for the government. Given Dutton's own opposition to same-sex marriage, it shows a pragmatic side to his politics that is often under-appreciated.

For at least two years colleagues have seen him as Turnbull's successor-in-waiting.

The thinking is that Dutton would provide a sharper point of difference with Labor and capitalise on Shorten's own unpopularity with voters. Turnbull - who prides himself on his non-ideological approach to policy-making - has sought to narrow the divide between the two parties on health, school funding and climate change.

By contrast, Dutton would maximise conflict, including by shifting the Coalition to the right on immigration by cutting the number of migrants who enter Australia.

From this perspective, the fact he so antagonises left-wing politicians like the Greens' Nick McKim (who has called him a "racist and fascist") and Labor's Tanya Plibersek (who on Tuesday said he had a "cold, shrivelled soul") is an advantage.

The hope is that this would win back conservative voters in Dutton's home state of Queensland, who have been drifting towards One Nation. Liberal moderates counter that Dutton's brusque, blokey style would likely turn off voters in states like Victoria and South Australia.

Dutton needs to pick up just eight party room votes to seize the prime ministership. Popularity can wait; winning power comes first.