When you look at the economy of South Australia it's not surprising many voters are thinking the state could use a politician who sings from a different economic song sheet than the two major parties, writes Greg Jericho.

In this election, for the first time in a long time, South Australia is a live state - where the results will likely have a significant impact on the national picture (especially in the Senate) and where the result in a number of seats is up for grabs.

Overwhelmingly this is due to the rise of the Nick Xenophon Team, whose stance on free-trade agreements echoes that of candidates in the US presidential election, such as Bernie Sanders, who found success in similar manufacturing-dependent areas where it was a struggle to show the benefits from such agreements.

The latest Newspoll published in The Australian this Monday noted that in South Australia the Nick Xenophon Team was polling at 29 per cent. Such a high level of polling means that a number of seats in South Australia are now in play and there is a good chance the NXT will claim four of the 12 senate seats in that state.

The rise of the NXT has led to some pretty strong reactions from the conservative side of politics and the media. The Australian and Australian Financial Review have featured articles that included sharp criticism of Xenophon's stand on free-trade deals and have run with the line that his brand of protectionism would kill jobs.

The Liberal Party, worried that the NXT might win seats such as Mayo, held by former government minister, Jamie Briggs, brought out John Howard to campaign for the seat. While doing so the former prime minister compared Xenophon to Pauline Hanson and Donald Trump.

Such a suggestion is pretty silly. Xenophon has no history of supporting the racist points of views that are the bread and butter of Hanson and Trump.

Being rather sceptical of free-trade agreements does not make you racist; it more likely means you have not swallowed the exaggerated sales pitch of the free-marketeers. Neither does it make you an economic troglodyte; rather, as I noted last week, the Productivity Commissions itself found few actual benefits of Australia's current free-trade agreements.

And when you look at the economy of South Australia it is not surprising that many voters are thinking the state could use a politician who appears to be singing from a different economic song sheet than the two major parties.

Of course the biggest reason for the rise of the NXT is the massive own-goal kicked by the Abbott government over its handling of the submarine issue.

After promising to build the subs in South Australia at the 2013 election, in 2014 the then defence minister David Johnston appeared to walk away from the promise and for good measure suggested that he wouldn't trust the Australian Submarine Corporation "to build a canoe".

The moment those words were uttered, South Australian seats held by the Government came into play - even after news that a French company had won the contract and would build the subs in Adelaide.

In the wake of Holden announcing it would cease production in the state, it's not surprising that telling voters of the wonders of Japan, Korea and China free-trade agreements has not been met with mass celebrations.

The reality is the post-GFC period has not been good for South Australia. While employment during the mining boom years grew much in line with the rest of the country, that changed once the GFC hit:

In the past 12 months employment growth in the state has been well below the national average. While Western Australia is experiencing worse employment growth, that state at least has had some good times since the 2013 election. South Australia, however, has had the worst employment growth of any state since the last election:

Only Tasmania has a lower percentage of its adults in employment. South Australia's employment to population ratio of 57.6 per cent is well below the national average of 61.1 per cent. It also is the state with the lowest percentage of full-time workers:

It is also much more dependent upon manufacturing than other states. While the manufacturing industry employs 7.5 per cent of all workers across Australia, in South Australia 9.1 per cent of workers are in the industry:

It also employs more people in the health care and social assistance industry than other states - reflecting that its population is older than the national average:

So it's a state where employment has flatlined for about five years, the proportion of employed is lower than most of the country and the proportion of full-time employed is the lowest. And the industries in which it is more dependent for work than other states are industries such as manufacturing, agriculture, health care and retail trade where workers have lower earnings than the overall average.

Not surprisingly, South Australian workers have the second lowest average weekly earnings in the nation. In November last year the average worker in South Australia earned $1030 a week (in trend terms) compared to the national average of $1146.

But where the lack of economic zest in the economy really shines through is in the lack of earnings growth. The shift from full-time to part-time labour, and the preponderance of employment in lower income industries means the state has experienced the worst growth of average earnings in both the past year and since the last election:

For anyone who has lived or grown up in South Australia (as I did), such information is not so much surprising as depressingly familiar.

Like Michigan in the US, South Australia is a state where voters are ripe for listening to someone who may not always trumpet the standard neo-liberal lines about free-er trade leading to greater prosperity and stronger GDP growth.

It's why perhaps a better comparison is not Trump or Hanson, but Bernie Sanders.

Pointedly, Michigan was the biggest state won by the Democratic Party hopeful in the recent primary race. Sanders ran on a platform that was strongly against free-trade agreements such as the NAFTA and the Trans-Pacific Partnership.

Clearly those in favour of free-trade agreements have done a lousy job of selling their benefits, mostly because those benefits are very unequal, and both here and in the US they have not been good for major manufacturing.

It's wonderful to whip out the economic modelling and marvel at how greatly the demand curve will shift if certain policies are enacted. One of the large problems for Malcolm Turnbull and his sales pitch for the company tax cut is the talk initially was very much in the macro-sense - growing the pie for all, extra percentage points of GDP growth at some later date.

He wasn't able to point to much actual evidence of such policies generating strong growth outside of an economic textbook.

And for workers who have seen factories closing down over the past decade, and are treated with contempt by the federal government, the lack of evidence is rather glaring.

Populism thrives when voters begin to wonder whether, when politicians from the major parties have told them that the economic suffering they are enduring is for their own good, that they really meant it was for the good of someone else.

Greg Jericho writes a weekly column for The Drum. He tweets at @grogsgamut. His personal blog is Grog's Gamut.