You don't often get business journalists quoting Karl Marx. Groucho Marx, maybe, when they want to leaven their economic ruminations with a one-line zinger fresh from the middle of last century. But the Father of Communism? Not so much.

Yet there he was this week cited in the middle of an online essay by Bernard Hickey, one of the country's most articulate and prolific business commentators.

Entitled "The free market god doesn't exist", Hickey's piece declares that the economic model New Zealand has stuck to for nearly 30 years has been revealed to be a failure.

He recants his former belief in the primacy of markets and economic freedom and says, "We have to assume, just as Marx pointed out, that free markets will eventually overheat and blow up if we allow them free rein."

Now Hickey is no crank. Might his mea culpa reflect a sea change in mainstream thinking about the orthodoxy we've followed since the mid-1980s? Quite possibly. In tough times people are wondering what got us into this debt-ridden mess.

Coincidentally, the economic model's original local architect has been back in the news. Roger Douglas exhibited all his usual modesty and charm in a limp poke at the Prime Minister. His flyer had a photograph of himself, naturally, as well as one purporting to show Key with his head in the sand.

This damp squib - in response to Key's declaration that he could work with anyone as Act leader, except Douglas - served only to underline how irrelevant Douglas has become.

If he was really looking for laughs couldn't his photo have been a snap from that taxpayer-funded trip to London to see his grandkids?

Key's repeated snub shows again just how little public sympathy the ultra-pragmatist Prime Minister believes there is for Douglas and his ideas. Does it follow that the building blocks of Rogernomics left in place by successive Governments will also be increasingly questioned? If Key sees enough votes in it, you bet.

Phil Goff, who also seems to believe in giving the electorate what it wants, has already promised to drop the GST on fresh fruit and veges, a move that would dilute the purity of the tax Douglas first imposed. Bill English scoffed but that kind of tinkering is now on the agenda.

Purity doesn't seem so important.

Key and English themselves have left wriggle room on foreign ownership of our farms. Hickey calls for a debate on monetary policy and asks why New Zealand shouldn't have Singapore-style controls on capital flows and exchange rates.

There's an awful lot of room between Douglas and well, Marx, in which less ideologically constrained politicians can look for solutions to our economic problems.

Meanwhile, another part of the Douglas legacy is also under threat. He probably doesn't list MMP as one of his achievements but he should. It was Labour's lurch to the right in the '80s, then Douglas soulmate Ruth Richardson's unique spin on National's "Decent Society" that created a public appetite for change.

Their willingness to ram through policies nobody ever voted for (their fans call it "leadership") meant voters stopped trusting the system.

Over the next couple of elections we're going to find out whether we're ready for another change. And this time it's suggested that recent shenanigans in Act increase the likelihood of MMP getting dumped.

The argument seems to be that the public, losing patience with the sideshows of self-important fringe politicians, will want to ditch the system which promoted them.

In truth, we've always had fringe politicians getting more than their fair share of attention. Anyone remember Marilyn Waring or Mike Minogue?

Another anti-MMP line is about hacks on party lists. Well, there was no shortage of ineffectual hacks back under the old system. They were the drudges political insiders smirkingly called "good electorate MPs".

And look at the contributions made by the likes of Jeanette Fitzsimons, a recycled Richard Prebble or even Hone Harawira, when he took on the tobacco companies. Would we want less chance of people like that having a voice in Parliament?

Yes, putting things back more firmly in the control of the two big parties would mean greater opportunity for Douglas-style "leadership". That's always going to be attractive to people who think they have all the answers.

True Rogernomics believers scent another opportunity. But the world has moved on, most markedly as a result of the global financial crisis. In messy times, it's best our politicians don't limit their policy options.

The other Marx, the one with the cigar and wriggly eyebrows, knew all about the value of flexibility.

"Those are my principles," he said once, "and if you don't like them ... well, I have others."