The most important message from Sky News’ two-part documentary Bad Blood/New Blood, which aired on Tuesday and Wednesday, was provided by Home Affairs Minister Peter Dutton. He said the Liberal Party was in the best position it had been in for some years.

The Coalition’s defeat by Labor in March 2007 saw the incumbent prime minister John Howard lose his seat. He was replaced by Brendan Nelson as Liberal Party leader, who was replaced by Malcolm Turnbull, who was replaced by Tony Abbott. Abbott led the Coali­tion to a near victory in 2010 and a big win three years later.

There followed the instability of the Abbott-Turnbull governments. When Abbott lost the support of the partyroom and was replaced by Turnbull in September 2016, this was accepted as part of the political process. But when Turnbull lost the support of the partyroom in August last year, he accused those who moved against him of engaging in acts of terrorism. In fact, Turnbull was fortunate to retain his leadership position following the debacle of the 2016 election when the government lost 14 seats to Labor. When the Liberal Party primary vote dropped below 30 per cent in the Longman by-election in July last year, it seemed evident that Turnbull would struggle to lead the Coalition to this year’s election. And so it came to pass.

Dutton and Howarth came from electorates close to Longman and both could see that their political careers were threatened by political defeat. Moreover, they genuinely believed the election of a Bill Shorten-led Labor government would be bad for Australia.

In the week beginning Sunday, August 19, Dutton began talking to some of his colleagues about a leadership change sometime in the future. And Howarth told Turnbull supporter Craig Laundy (the member for Reid) the prime minister should step down. It was the latter conversation that was the immediate cause of the turmoil that followed.

Following his conversation with Laundy, Turnbull decided to move a spill of the leadership in the partyroom on Tuesday, Aug­ust 21. It seems that Turnbull’s deputy Julie Bishop was made aware of this decision. But, among his political colleagues, Turnbull took advice only from Laundy. Laundy told Bad Blood/New Blood about the honour of advising Turnbull when he (Laundy) had been a member of the Liberal Party for only 6½ years. Enough said.

Dutton decided that he would oppose the prime minister’s motion. Turnbull won the vote 48 to 35 — scoring just 58 per cent of support from his colleagues.

At this point it was all over. Ministers and backbenchers alike deserted the prime minister. Even after Turnbull abandoned the Liberal Party practice of a secret ballot for leadership contests, 43 Liberals (a majority of the partyroom) put their name to a petition calling for a leadership ballot. Turnbull stepped down and Scott Morrison defeated Dutton on Friday, August 24.

Senate leader and Finance Minister Mathias Cormann also made a significant contribution to Bad Blood/New Blood. He pointed out that loyalty does not require following your leader over a cliff. As early as September 2017, in an address to the Sydney Institute, Cormann set out what was to become the Coalition’s economic narrative for this year’s election. He did not deviate from that position.

Cormann framed the Shorten-led opposition as being intent on a socialist agenda of bigger spending financed by higher taxes and increased regulation. Cormann regarded it as more important that Labor be deprived of office than to stick by a leader who had made a series of unforced errors.

In the wake of Turnbull’s replacement by Morrison, many a journalist — particularly in the ABC and Nine newspapers camps — kept asking Liberal politicians why they had replaced the leader. The question need not have been raised. It was the same reason that applies to all leadership changes; namely, that the incumbent has lost the support of most of their colleagues in the partyroom. That’s all.

There was a widespread view among the Canberra press gallery that only a leader such as Turnbull or Bishop could lead the Coalition to victory and that neither Morrison nor Dutton could win in 2019. Then why did Turnbull lose so many seats in 2016?

On May 18 Morrison won back from Labor many of the seats Turnbull had lost three years earlier: Bass and Braddon in Tasmania, Lindsay in western Sydney, Herbert and Longman in Queensland.

In other words, last month Morrison gained some of the ground Turnbull lost in 2016. Labor’s principal gains were due to the creation of a new seat in each of Victoria and the ACT. Also, Labor won two seats in Victoria (Corangamite and Dunkley) that had become notionally Labor following an electoral redistribution.

On the ABC TV Insiders program last Sunday, Nine newspapers’ David Crowe and ABC Radio National’s Patricia Karvelas speculated that Bad Blood/New Blood might spark new tensions in the Liberal Party about how Morrison got the top job last year.

It won’t. The fact is that Morrison won an election that many thought was unwinnable. Moreover, under the Liberals’ new parliamentary party rules, an incumbent prime minister cannot be challenged during their term. And the likes of Dutton, Cormann and Josh Frydenberg got what they wanted — a Coalition government and a Labor opposition. All is quiet on the leadership front and the Liberal Party is in as good a position as it has been since around 2004.

Gerard Henderson is executive director of the Sydney Institute. His Media Watch Dog blog can be found at www.theaustralian.com.au