A little over two and a half weeks ago, Leigh Sales asked Malcolm Turnbull a very pointed question: “You have been prime minister now for nearly two years. How is it possible that, in all of that time, you’ve not yet managed to have a signature achievement?”

Turnbull, obviously taken aback, began by nominating changes to schools funding. Sales parried, saying that was initiated by Labor. Turnbull said, what about restoring the Building and Construction Commission? Then he added reducing company taxes, and reforming childcare. He added Snowy Hydro (Sales pointed out it was only a feasibility study so far). He listed a strong economy, and keeping Australians safe from terrorism.

At one point in the midst of this, Sales said, “But do you really want historians to look back and when they look for your signature achievement they go, ‘Oh, well, it was the continuation of a Labor policy, it was the company tax, it was the ABCC’?”

No prime minister likes to be called a minnow, which was effectively what was happening, and you can see why Turnbull was frustrated: some of the items he listed are not small achievements. But to say so demands that I add the following, for completeness: most of them are not, either, what you could call large achievements.

A while back I outlined a pet theory of mine. It’s entirely subjective, isn’t based on the slightest sliver of statistics, and is not independently verifiable, so I wouldn’t place too much stock in it if I were you. As you’ll see, the nature of it changes over time, so it’s pretty fickle, too. It’s also more of a game than a theory. Still, here it is: think of a single term of any government – say Howard’s or Hawke’s first term. See if you can remember three things from that term.

That’s the first bit.

The second bit is this: were the three things good or bad? If they were mostly bad, the likelihood is that that government was vanquished at the next election and vice versa. To save myself time, here are my old examples:

“For Howard’s first term I had gun laws, waterfront, GST. It’s a close-run thing: good, bad, mostly good. Which is how that election turned out. Howard got fewer votes than Kim Beazley, but scraped into power. By Howard’s last election, the maths was clearer: WorkChoices (bad), Costello leadership chatter (bad), rising interest rates (bad). Goodbye Johnny.”

Anyway, whether you buy all this or not, the point of it is to remind you of how easy it is to get sucked into the moment-by-moment, play-by-play motions of politics, and how little of all that actually sticks.

So, for example, right now we’re in the middle of three political issues. The first is the dual citizenship circus. That will always be of interest to historians, because the judgement of the High Court will last. But politically, I suspect it’s only likely to make the cut-of-three if Barnaby Joyce is disqualified, and even then only if that somehow brings about the fall of the government.

The second is the same-sex marriage vote. There is no question, for me, that this will be one of the three. Either result will be momentous – No as a disaster for Turnbull, Yes as an historic shift in the law. Will that be an upside for the PM, though? Given the tortuous way it’s got to this point, I’m not sure. But it certainly could be – the point of this exercise is that history smooths out the smaller events, and picks only the major peaks. A change in the law will be a massive event. Still, it’s a tricky one, because many of the people most in favour of change will forever hold Turnbull responsible for the plebiscite, which they deplore.

The third is power prices. Power prices matter to families. Blackouts matter to families. This should be important, and certainly if major blackouts occur then we’ll all remember them. But what would an upside actually look like for Turnbull? The passing of a Clean Energy Target, of which most Australians have not heard, and certainly do not understand? (I include most politicians in the second category.) And when was the last time a government got credit for falling prices? Turnbull may survive the CET debate, but it’s hard to see it becoming a memorable win.

Which brings us back to Sales’ point. Two years in, and Turnbull does not have a signature achievement. That isn’t the same as saying he has no achievements. I’ve repeatedly praised the first item he listed, his school funding changes. But there is still nothing readily identifiable with him. Nothing to embed a sense of him in voters’ minds. Nothing that yells “TURNBULL!”

He can’t admit this out loud, of course. But he must acknowledge it to himself, because acceptance is the first step towards doing something about it.

Turnbull has one factor on his side, kind of. That is the fact that, while he is two years into being prime minister, he is only one year into this term. At this point in his first term, to pick one example, Howard had delivered gun reform, but voters had yet to hear about either the waterfront dispute or his GST plan. In other words, only one out of the three major events had seen the light of day. This might be compared to where Turnbull is, given that the same-sex marriage plebiscite is well and truly under way.

But the comparison does not entirely work, because of two ticking clocks. The first is the Newspoll counter that Turnbull set when he challenged Abbott – two years ago today – which will run down a long time before the next election is due. The second is that, for various reasons including the timing of state elections, the next federal election is likely to arrive sooner than is usual, perhaps by September next year.

So, what’s the upshot of all this? In order to win the next election – or even to survive until then – Turnbull is not where he should be, not remotely. Nor is he completely down and out. But if he is to have any chance at all, he better get cracking. The next time Sales asks him that question, he will need a better answer. If he hasn’t got one, it will already be too late.