"It won't be a uniform swing…but it doesn't take a lot to sweep the Liberals into office," he said.
The Weatherill government appears to be grappling with the disappointed voter, he said.
This sense of disappointment began in August 2012 with the cancellation of the expansion of Olympic Dam followed by the loss of the AAA rating and compounded by the internal divisions, Associate Professor Manning said.
However, on any given day the State Government's fortunes could radically change, he said.
The inexperience of Stephen Marshall (who entered parliament in 2010) plus the decades long history of SA Liberal internal divisions could derail the campaign, he said.
"It really is Mr Marshall's campaign to lose," he said.
SA Premier and Treasurer the Hon. Jay Weatherill said South Australia is at an important crossroads and he wants a serious debate about the future direction for the state.
"I believe this is an incredibly important election and I think the community think it is an incredibly important election," he said.
"The SA community and SA economy is at an important crossroads and the challenges in front of it are enormous.
"They're urgent and they're not going to be solved by someone just taking their hands off the wheel and saying 'let's get out of the way'.
"If there has ever been a time for a government to stand up and lead, and actually provide a vision of the future of this state, it is now.
"When we think about how we're going to respond to our challenges, we need to also remember that it needs to occur in a context where we don't sacrifice what we have created here."
Mr Weatherill said the SA economy is stronger and more diverse than it was 12 years ago and has almost doubled in size since 2002 from $52 billion to $95 billion, which includes:

• $300 million per annum more expenditure from international tourism than in 2002;
• The creation of a renewable energy industry; and
• 25 per cent of the nation's defence build (in a state with approximately 17 per cent of the population)

In addition, Mr Weatherill said since 2002, the state's crime and elective surgery wait times have decreased and increased school retention rates.
"So when we embark on the notion of what should change to meet our undoubted challenges, let's not sacrifice all that we have created here.
"If this is a voter choice election I believe people will choose to keep building."

Global and Australian economy

Despite a lower growth rate, China still represents a large amount of global consumption, which in conjunction with a pick-up in the US, is good for Australia, ANZ, Senior Economist, Justin Fabo has told a CEDA audience in Adelaide.
Mr Fabo said while China's growth is expected to stay around seven per cent, down from 10 per cent per annum growth for 30 years, Australia should benefit from an increase in Chinese tourist visits and spending as well as an increase in resource export volumes.
Mr Fabo also said ANZ forecasts are for the AUD to go into mid-eighties against the USD in coming months and stay there for the rest of the year.
"The price we receive for some of our [exports] will come off but the volumes are going through the roof," he said.
While most signs were positive for the Australian economy including business and consumer confidence, global growth, non-mining investment, building approvals and housing prices, the key downside risk was Australia's terms of trade coming off too quickly, Mr Fabo said.
"If it fell another 20 per cent in short succession, all bets are off," he said.

Federal politics

On federal politics, Former Australian Minister for Foreign Affairs Alexander Downer AC said the Federal Government's priorities will be fiscal consolidation and infrastructure.
The government has front-end loaded all the costs into this financial year to blow the deficit out as much as they need to in this financial year, which means that when you get the budget in May you're told it will be a horror budget, he said.
"Without getting substantial rates of economic growth over the next few years, they're not going to get back into surplus," he said.
Mr Downer also said how the government structures a policy to create a more attractive environment for private sector investment in infrastructure projects will be a priority.
The Federal Government is sending a strong message to the states on infrastructure, he said.
"The states have $135 billion worth of assets that could be privatised and the Federal Government would like to see them privatise those assets and reinvest the proceeds of privatisation into infrastructure projects," he said.
CEDA members can access event audio and presentations here.