South Australian marginal seats key to next federal election FOUR South Australian marginal seats will become key battlegrounds at the next federal election. Swings of between three and eight per cent helped the Liberal party narrowly claim Hindmarsh in Saturday's poll and reduce the Labor-held seats of Adelaide, Makin and Wakefield to marginals. The result reflects the state of play last time the Coalition held government, when those four seats and the electorate of Kingston received significant attention from both major parties. The same is likely to occur over the coming three years as they battle to maintain their influence in SA. Liberal insiders say the party poured resources into Hindmarsh, believing Mr Williams was their best chance to claim a scalp, but some have privately suggested more competitive candidates must be chosen in seats like Adelaide and Makin which are within reach next time. Mr Williams already has an eye on the next poll, telling reporters yesterday his party was now "closer to claiming those (marginal) seats." He rejected suggestions from senior Labor MPs that the South Australian Liberal branch was the "poor cousin" of its interstate counterparts for not snatching more ground from Labor. Liberal Senator Simon Birmingham, who has known Mr Williams for about 20 years and played a key role in his campaign, said while the party "would have liked to have won more" it was "ecstatic to again hold a majority of seats in SA and have made a contribution to the national victory." To hold on in Hindmarsh, Mr Williams will want to make good on a promised $2 million upgrade of Henley Square and keep concerns about the Adelaide Airport curfew under control. In the electorate of Boothby - where the Liberal party increased its margin - incumbent Andrew Southcott will benefit at the next poll if an Abbott Government delivers on a pledge to spend $500 million upgrading the Darlington Interchange. In Wakefield, the future of the Holden carmaking plant at Elizabeth will continue to be a battleground. The Coalition has flagged a $500 million cut from a national car industry support fund, but claims removing the carbon tax will help lower the cost of production in Australia. Adelaide University political analyst Clem Macintyre said tighter margins in SA seats would benefit residents as the major parties fought to secure their vote. "It's always better (for voters) to be in a marginal seat than one that is taken for granted by one party or the other," he said. South Australians next go to the polls for the state election in March, 2014. Prof Macintyre said that outcome would also influence which SA electorates received most attention federally. "The focus on SA federal seats will depend on whether it's a fourth-term (state) Labor Government here or a first-term Liberal government under (Opposition Leader) Steven Marshall," he said.