Luckily for Malcolm Turnbull, who seems to have absorbed several blows in recent days, his plan for Australia had change as its central feature. Remember it? Change is our friend, our ally, we've got to be nimble, agile ... yada, yada, yada.

But in fairness he wasn't thinking about government so much as the broader economy. From his side of the fence, the Turnbull prospectus promised stability and predictability in Canberra. A return to orderly Westminster processes defined by cabinet government, the sober pluralism of collective decision-making.

At the end of the first parliamentary fortnight for 2016, however, that promise lies in tatters.

A faux tax reform debate, which had squawled up like a summer storm around a bigger GST, was circumnavigated, delivering barely anything useful.

This was the Turnbull response to a galloping scare campaign by Labor. At no point did the central elements of the GST proposal, its potential design parameters, and the government's view of the relative merits of one formula over another, emerge. Instead, for the untidy duration of the GST focus, the government stuck like a limpet to the intellectually sparse proposition that it was hosting this "national conversation" while refusing to nourish it in any way.

Government MPs were livid at the opposition's "rank opportunism". Yet Labor was no more disreputable in framing the outer limits of the GST plan – i.e. the worst case scenario for consumers – than was the government for stubbornly refusing to risk its hand.

Turnbull's retreat on the GST expansion at the first whiff of grapeshot has punctured the overblown expectation created around his ascension, of new and purposeful economic leadership based on explanation rather than slogans. The double irony is, faced with Labor's almost Abbott-like anti-GST sloganeering, Turnbull's only persuasive contribution was to "explain" why he was in retreat – why the GST's inherently tricky politics rendered its economic gains too expensive.

One obvious conclusion to draw from all of this is that like the refusal to put same-sex marriage equality to a free parliamentary vote, or even to lend qualified support to a new republican push, the government's political interests come before the oft-invoked national interest.

Take marriage equality. It is demonstrably true that right now allowing same-sex couples to marry enjoys vast public acceptance, and majority support in the Parliament – both houses. Yet, for nothing other than the internal political interests of the Liberal Party and of Turnbull's leadership itself, that vote will not take place.

Turnbull's new defence of a plebiscite that is not needed and which he never supported is to ask what the ALP has against democracy. As an argument uttered in the Parliament, the very fulcrum of Australia's representative democracy, it is embarrassing.

Beyond its different rhetoric and last year's high-profile but fiscally modest innovation statement, the Turnbull government is yet to achieve substantial policy differentiation from the Abbott period. Indeed even the transformative power of the innovation statement, with all its lofty aspirations for the knowledge economy, has been eroded after the fact by the continuation of Abbott-era policies such as refusing to commit to the final two years of Gonski education funding to the states, and the looming budget-driven job losses in the CSIRO – the very venue for the innovation statement in December.

While it is tempting for observers to blithely declare the honeymoon over, that will be up to the voters. Has the GST debate spooked them, or caused them to reflect on substance rather than spin?

That is not yet clear. But other events this week cannot have helped. The revelation that the government has quietly pushed ahead with another Abbott policy since forgotten, to outsource Medicare's payment system, is a sure vote loser – even if it makes sense. Justifying it will take all of Turnbull's prodigious advocacy skills.

According to one Labor MP, the optics of a Coalition government privatising Medicare are even more advantageous for Labor (insert perilous for Turnbull) than the GST hike. The first-term member said Medicare was already the dominant issue bringing business to his outer-suburban electorate office this week in what feels like a rerun of the tsunami of anxiety over Abbott's disastrous GP co-payment.

If that is universal, the Medicare payment reforms will be as much a lifeline for the opposition as the GST hike – a hike scotched for pretty much that reason alone.

And then there's the ministry. When you tote up the ministers lost from the frontbench this term, it's not long before you get to double figures. Since Christmas, Turnbull has lost one to resignation (Jamie Briggs), has a cloud hanging over two more (Mal Brough and Stuart Robert), and has seen two of his most dependable senior cabinet colleagues announce their retirements on Thursday (Deputy PM Warren Truss and Trade Minister Andrew Robb).

Rumours surround another cabinet figure, which if true, would end his career also. One Turnbull insider admitted things appeared "untidy" and even perhaps "out of control" but insisted that was not the case.

The Turnbull operation is struggling between the reality of having to start most government policies and activities afresh and the unreasonably high expectations the change of leaders created.

In the cases of Brough and Robert, Turnbull has been lumbered with infractions which predate his own prime ministership. But he appointed these ministers and thus owns their respective pasts as much as their contemporary performances.

Brough's fate turns on an AFP investigation into the Ashby-Slipper affair. Robert's on the PM's own application of the ministerial code of conduct.

The coming reshuffle will clear the air, and Turnbull hopes, give him time to duck the next punch coming his way.

Mark Kenny is Fairfax Media's chief political correspondent.