As the Government faced its first post-coup parliamentary day, the enormous gamble the Liberals had taken was obvious.

It isn't just that big "transaction costs" of felling a prime minister are coming back to be paid.

It's that leading Liberals can give no halfway convincing rationale for an upheaval that has pushed the Coalition's two-party vote substantially backwards in Newspoll, and further baked in the community's anger with politicians.

No presentable 'narrative' for Liberal coup

We talk about "narratives" in politics. This coup does not have a presentable public "narrative".

In Parliament and the media, everyone this week is demanding answers to the "why?" question. No doubt Liberal MPs have been belted with it in their electorates during their short break among the voters.

Scott Morrison talks about the new (post coup) generation of Liberal leadership. As they struggle to explain the inexplicable, this looks more like the old generation heavily bandaged after a bar room brawl.

Some are not even pretending.

Deputy Liberal leader Josh Frydenberg was up front on Sunday about the National Energy Guarantee being ditched.

"No-one is more disappointed than I am", he told the ABC. As to why Mr Turnbull was sacked: well, he'd just leave that to the commentators to discuss.

On Monday, arguing the Government's defence against Labor's (unsuccessful) attempt to launch a censure, Leader of the House Christopher Pyne made the frank admission that "changing the leader is not the right thing to do".

"The Australian public are quite rightly most disconcerted with what's occurred," he said, but it was Labor's fault because they'd started the process.

"I agree with the Australian public that what they want is stability."

After dodging and weaving, Mr Morrison told Parliament: "The party chooses the person they want to lead to ensure that we can put the best foot forward at the next election and to ensure that we are connecting with Australians all around the country."

Insofar as there can be any hygiene in such a business, Mr Morrison has been able to claim relatively clean hands.

But Senate leader Mathias Cormann, whose withdrawal of support delivered a fatal blow for Malcolm Turnbull, clearly soiled his hands on the way through and struggles to explain.

When his shifting positions were put to him in Senate Question Time, his defence was one of I-meant-it-when-I-said-it.

"All of these statements were, of course, entirely accurate at the time," he maintained.

A male frontrunner for Liberal preselection in Wentworth this week withdrew, saying the party should choose a woman. ( ABC News: Nick Haggarty )

Right's grab for power killed Turnbull

Boiled down to its essence, the core answer to the "why?" question is that the Liberal Party's right — surely it is time we called them "the right" rather than "the conservatives" — made a grab for power that killed Mr Turnbull, although they didn't have the numbers to install their man Peter Dutton.

There were other important factors, but that was at the heart of it.

Mr Morrison and his colleagues can't, however, say that.

They have to indulge in non-answers or fudges until the media get sick of asking the why question.

One of the coup's back stories has been about the media, because it has highlighted the growing power of the shouty commentators, and the move of Sky's evening programming towards the Fox News model.

The always-forthright Liberal backbencher Warren Entsch called out the role of certain media commentators who, he suggested, became players in the coup.

Asked about the actions of some sections of the media applying pressure during the coup week, Mr Entsch said: "I thought it was an absolute disgrace. I don't think Sky News in particular wrapped themselves in glory."

He told the ABC: "I actually saw texts coming through to colleagues encouraging them to get rid of the prime minister, from some of these commentators. And to me, that's overstepping the line."

Their "absolute dislike" of Mr Turnbull was obvious, he said: "There was nothing that the former prime minister could have done to satisfy their obvious hatred of him. And they took every opportunity to actively have him removed."

Future is looming as scary for Liberals

The Liberals won't be complacent after a 28-point drop in Liberal support in the Wagga Wagga by-election, won by independent Joe McGirr. ( Picture: Facebook )

If the past is beyond explanation, the future is looming increasingly scary for the Liberals.

The Wentworth byelection — despite a 17.7 per cent buffer — is shaping as a close-run thing.

If any Liberals were complacent about Wentworth, they won't be after the weekend Wagga Wagga state by-election, where community-based independent Joe McGirr took the seat after a massive 28-point drop in the Liberal vote.

How much damage could a similar candidate do in Mr Turnbull's old seat? Probably a great deal.

Kerryn Phelps, who is set to run in Wentworth, is (like Dr McGirr) a medical practitioner. She is well known, with a general practice in the electorate.

Most recently she received plenty of publicity during the same-sex marriage plebiscite.

Wentworth a by-election for the history books

On Monday, Andrew Bragg, who had quit his Business Council of Australia job to seek Liberal preselection and had been considered one of the frontrunners, withdrew.

Whatever influences were at work there, Mr Bragg's public explanation was that the party should choose a woman.

The leading women in the preselection race are Mary-Lou Jarvis, a NSW party vice-president and president of the NSW Liberal Women's Council, and Katherine O'Regan, chair of the Sydney East Business Chamber.

Whoever becomes the Liberal candidate, this is potentially one of those by-elections for the history books.

It will be hugely expensive, just when the Liberals face a NSW election and the federal election. The cost will only be exceeded by the stakes.

If the Liberals don't hold the seat Morrison goes into minority government, with the angst that would bring.

In the meantime, in the campaign the Wentworth voters will want better answers than we're hearing now on why the party deposed their man.

Michelle Grattan is a professorial fellow at the University of Canberra and chief political correspondent at The Conversation, where this article first appeared.