For the most unwatched leaders’ debate in the 32-year history of the ritual, last Sunday’s joust caused a huge rethink of the Liberals’ campaign. Though most of the paid commentariat thought it was either a narrow Turnbull win or a draw, it was in fact a wake-up call for the prime minister.

One of the keenest watchers of the highly structured televised tableau was Grahame Morris. No amateur political tragic, Morris was John Howard’s chief of staff in opposition and in government. When he wasn’t doing that, he was running on-the-ground campaigns for the Liberals, especially in difficult byelections. Now a commentator and consultant, Morris laments the fact that neither Channel Nine nor Channel Seven televised the debate. For him, the essential missing ingredient was the “worm” and the “people meter”.

If business is miffed that the Coalition is going softly on tax cuts, they’re not showing it. But on the Coalition’s own timeline, it’s not at all certain they’ll be in power long enough to deliver the whole plan.

As the spiels unfold, these devices give instant reaction from a panel of uncommitted voters. Morris is convinced the worm would have scored Bill Shorten a clear winner. “Malcolm was talking to the room,” he said. “Bill was talking to the lounge room at home.”

There’s no doubt Turnbull’s presence at the podium would have scored high marks in strict debating terms, but this was no high school debating competition. It was a contest to convince voters that what one or other of the participants had on offer was best for them and, coincidentally, for the nation.

At the campaign’s halfway mark – the beginning of week four in an eight-week marathon – Turnbull came with the same pitch that had failed to break the 50-50 deadlock in the polls: “I have a plan. My government has set out a national economic plan, every single element of which will create stronger economic growth and more and better jobs for Australians in the future.”

Shorten came with a refinement of the arguments that have put him in the hitherto unlikely position of being highly competitive. He went straight to Medicare, education and training, and housing affordability. He promised action on climate change and renewables and equal treatment of women in society. He said: “By contrast, our opponents have got a plan which puts big business at the centre of their economic strategy.”

He described the Turnbull plan’s centrepiece $50 billion 10-year tax cut for business as a “very expensive risk”. Further, he identified $7 billion worth of tax cuts going to the four big banks. “Much of this money will go to overseas shareholders. It will derive little economic benefit.”

Support for these propositions is found in Treasury’s own analysis. Finance Minister Mathias Cormann had no quibble either. He told Sky News that over the long term it would increase the size of the economy by 1 per cent. He defined the long term as “a period up to 20 years”. In the debate, Shorten argued the money would be better spent on his prescriptions.

Goldman Sachs, Malcolm Turnbull’s old bank, put out an analysis that lent weight to the assertion that the tax cuts would see 60 per cent of the benefit going to foreign investors in dividends: “Survey evidence suggests that companies are less likely to voluntarily lower the dividend payment ratio.”

Shorten’s killer lines – “He wants to give [the big banks] a tax cut; I want to give them a royal commission” – convinced Grahame Morris that the Turnbull pitch needed to be drastically refined. Liberal campaign headquarters apparently agreed, and by Tuesday the selling of the 10-year plan shrank to a four-year boost for mum-and-dad companies. These he defined as companies with a turnover up to $10 million. Labor is holding firm to its offer of tax cuts to small business under the old definition of a $2 million turnover. It argues dividend imputation already gives Australian investors tax relief.

Turnbull says that in the next three-year term the tax cuts will ratchet up only to companies of $50 million or less. “Then there would be another election.” In fact, he said there would be another election even after that before all companies – small, medium and large – saw their tax rate cut to 25 per cent. That undermines the credibility of his visionary 10-year plan. It sends the message that the plan is, well, “fantasy” – the very word he uses against Labor’s long-term Gonski education reforms.

Labor strategists believe the Coalition’s reliance on trickle-down or supply-side economic theory is disproved and old hat, and as a result no longer resonating. After all, companies or businesses don’t hire extra staff unless they need them to meet demand, especially as the tax cut is only worth about $8 a week. Demand is driven by customers having higher disposable incomes. It’s an argument that feeds into weekend penalty rates and higher minimum wages. The Coalition’s business mates are on the wrong side of that argument in the electorate.

Turnbull is accusing Shorten of a “war on business” in an interesting twist on class warfare. But if business, especially big business, is miffed that the Coalition is going softly on tax cuts, they’re not showing it. The Coalition’s firm ally, the Australian Chamber of Commerce and Industry, seems happy that the tax cut will be “phased” in over 10 years. But on the Coalition’s own timeline, it’s not at all certain they’ll be in power long enough to deliver the whole plan.

There is more trouble for the government from its own over the superannuation changes. Sky News is reporting a threatened backbench revolt in the party room after the election. West Australian backbencher Ian Goodenough tweeted that he’s received “a volume of correspondence from constituents objecting to the changes”. Even the assistant minister to the treasurer, Alex Hawke, admits rumblings. He denies a revolt, however.

A significant number of Liberal Party members in the better-heeled electorates are particularly protective of their retirement funding arrangements. Peter Costello as treasurer copped terrible grief when he introduced a superannuation surcharge in his first budget. He over-compensated a few years later when, flush with bulging revenues, he introduced the outrageously generous concessions that Scott Morrison has now trimmed.

Morrison and Turnbull are sticking to their guns. Liberal campaign HQ says they are proving popular with the broader electorate. Besides, the treasurer has little choice, given that shrinking the super tax concessions is critical to his budget repair strategy. But it didn’t help the government’s claim to competence when the Liberals’ deputy leader, Julie Bishop, could not explain one of the simpler changes, the transition to retirement tax from zero to a still concessional 15 per cent.

There wasn’t much sympathy for Bishop’s befuddlement from Tony Abbott’s old chief of staff, Peta Credlin. In her new role as a commentator she said the foreign minister, as a member of cabinet, should have known more as it would have been discussed there. Anyway, she said Bishop should have been better prepared, especially as 3AW’s Neil Mitchell has been raging against the super changes for weeks. Credlin said she was surprised as Bishop is usually on top of her brief. That was the problem. The speaking notes the campaign gave the minister omitted transition to retirement. What they did include she resolutely repeated to the querulous Mitchell.

Credlin also intervened to help put out a bushfire started by the Nationals leader, Barnaby Joyce. In an outburst of honesty, the deputy prime minister told AAP that he believed Tony Abbott still harboured leadership ambitions. He’s quoted as saying: “He will want to, but he’ll realise he can’t.” Joyce believes reality will overcome that desire. Credlin said it was absolute rubbish: “I was going to say horseshit but I don’t know if I can say that on TV.” A month or two back, she thought there was no such thing as “never ever” in politics. Aware of the political danger in a tight election, she’s now jumped on board the team bus. Labor certainly sees the spectre of an Abbott return as something that scares voters. It is sure to revisit the prospect later in the campaign with something along the lines of “A vote for Turnbull will give you Abbott”.

And Labor will need something to get it over the line. There has been little real movement in the first half of the campaign. No government-changing momentum. The Coalition will lose seats, but not enough. Analyst Andrew Catsaras says the latest polls would translate on a uniform swing to 77 seats to the Coalition and 69 to Labor. With a crossbench of four, that is a scarily slim majority, close to minority status.

But the Liberals say they are tracking reasonably well in enough of the marginals. While they are finding disappointment in Turnbull, there’s no desire for Shorten. “Voters, or enough of them, want Turnbull to succeed,” is the view of one inside the Liberal campaign. And that brings us back to where we were four weeks ago. As the Liberal strategist sees it: “From that point of view we’re starting all over again from nil-all.”

The government this week began emphasising the $3 billion worth of fairness their super changes give to women and those on lower incomes. That, and they are scaling down rhetoric on their business tax ambitions.

Labor believes it has framed the fairness debate and now needs to harden up its economic “plan”. Shorten began using the word almost as much as Turnbull in the debate. A key plank in that economic story will be the centrality of a best-technology national broadband network as key infrastructure for the future.

They all hope the voters will begin taking notice.