An unusually eventful preselection season for the Liberal Party reached a new crescendo over the weekend, as preselectors in the blue-ribbon Sydney seat of Mackellar finally dispensed with the services of former speaker Bronwyn Bishop.

Bishop is the second lower house Liberal to get the chop ahead of the coming election, following on from Dennis Jensen’s defeat in the Perth seat of Tangney a fortnight ago.

Coincidentally or otherwise, the victims on both occasions were right-wingers who had defied philosophical logic by backing Malcolm Turnbull to replace Tony Abbott as prime minister.

But in neither case was an ideological conservative the beneficiary — indeed, the result in Mackellar can be viewed as part of the moderates’ march through the party’s New South Wales branch, which now leaves Tony Abbott as the last conservative standing in the electorates of coastal and harbour-side Sydney.

Excluding an also-ran who scored two votes on the first round, the Mackellar preselection pitted Bishop against the eventual winner, Jason Falinski, and a close ally of Tony Abbott’s, Walter Villatora.

Falinski’s activities as a moderate operative over the years were apparently enough to ensure that Bishop at least had the support of the centre-right faction, which is all but synonymous with Mitchell MP Alex Hawke.

But for the hard right, which Bishop had courted since a very early stage of her lengthy career, the act of treason in supporting Turnbull was not to be excused, even if it did mean the seat went to a moderate.

When Villatora was excluded before the final round, his hard-right support flowed en bloc to Falinski, who, at this point, had assembled a coalition that cut across the alliance of moderates and centre-right that has dominated the state party’s affairs in recent years.

Things were a little more straightforward in Tangney, where Dennis Jensen had neither a factional backer nor a counterpart for Bishop’s inexplicably loyal base of local support.

Jensen had held the safe seat for over a decade without winning promotion off the backbench, and had twice been saved by higher forces in the party after losing ballots of local branch delegates.

It is unlikely Jensen could have stood up to a challenger with Ben Morton’s breadth of support under any circumstances — and certainly not after he alienated his natural conservative support base by moving to instigate Malcolm Turnbull’s leadership challenge.

For anyone without a dog in the factional and ideological fight, the outstanding fact of the two results is that the right decision was reached in each case.

It can always be argued that casting aside veteran members comes at a cost to the Parliament’s corporate memory — and on that score, it’s worth nothing that Philip Ruddock might have suffered the same fate as Bronwyn Bishop in his seat of Berowra over the weekend if he hadn’t quietly made way for Julian Leeser, former executive director of Liberal-aligned think tank the Menzies Research Centre.

However, the value to Parliament of Bishop’s wisdom and maturity had already been laid bare by her performance as speaker, while Jensen failed to qualify as an elder statesman in terms of either the length or breadth of his experience.

By contrast, the Liberal Party is likely to be well served in years to come by Ben Morton, who oversaw a period of outstanding electoral success as director of the WA Liberal Party from 2008 to 2014, and Jason Falinski, who has business experience as the founder of a successful healthcare equipment firm, and political experience as an adviser to former Liberal leader John Hewson and former NSW premier Barry O’Farrell.

If any doubts remain as to the often invigorating effect of the occasional spot of preselection ugliness, one need look no further than the heavyweights of the current Parliament who pried their seats from the cold dead hands of their predecessors:

Malcolm Turnbull. The Prime Minister and member for Wentworth was raised in the eastern Sydney electorate he now serves, and apparently had no thought of pursuing his destiny through any other path. Certainly, Turnbull was not to be deterred by the fact that the seat already had a fresh new member in Peter King, who would claim Turnbull had told him to “f**k off and get out of my way”. Turnbull prevailed in the preselection ballot by 88 votes to 70, then defeated King at the election when he ran as an independent. Not that King had much right to complain at his rough treatment; he had come to the seat three years earlier after blasting out Andrew Thomson, who could be heard on ABC’s 7.30 last Thursday complaining about the party’s preselection processes.

Bill Shorten. It did not actually come to a vote in this case, but the present Opposition Leader was able to secure his western Melbourne seat of Maribyrnong before the 2007 election when his predecessor, Bob Sercombe, saw which way the wind was blowing and went quietly. While Sercombe had a not insubstantial empire of his own within local branches, it was little match for the numbers Shorten could bring to bear as national secretary of the most powerful force on the national Right, the Australian Workers Union.

Christopher Pyne. Assuming he retains it at the next election — never a sure thing, and newly problematic in the face of the Nick Xenophon Team — the Education Minister will, by the end of the next term, have spent over half his life as member for the Adelaide seat of Sturt. As state president and then national vice-president of the Young Liberals, Pyne had already laid the foundation of his career as a moderate factional warlord by the age of 23. It was then, in 1991, that he won the right to contest Sturt at the 1993 election by toppling Ian Wilson, a “pillar of the Adelaide establishment” who first came to the seat in 1966.

Mark Dreyfus. As a Queen’s Counsel who had won the backing of the right, Labor’s current shadow attorney-general was formidably placed when he sought a seat in Parliament at the 2007 election. His target was the bayside Melbourne electorate of Isaacs, then held for Labor by the low-profile figure of Ann Corcoran. Dreyfus’ designs on the seat were not uniformly well received by locals, not least because he lived in more fashionable Malvern, and he was defeated by Corcoran in the ballot of local members. However, the result was decided for Dreyfus when the factional numbers of the party’s Public Office Selection Committee were added to the total.

Jason Clare. By the end of the Howard years, Paul Keating’s successor in the western Sydney seat of Blaxland, Michael Hatton, had become something of a byword for the safe seat-warmer who had too little to show for his career. With a return to power finally beckoning at the 2007 election, the party’s national executive seized control of the preselection, partly to ensure that Hatton made way for the Right-backed Jason Clare, Transurban executive and former staffer to Bob Carr, and now the opposition spokesman for communications.