Rudd became prime minister in 2007 but was ousted in 2010 by his then-deputy in an internal party showdown. He reclaimed the leadership on June 26 and changed several key policy positions, and Labor started gaining ground in opinion polls.Nick Economou, a Monash University political scientist, said Rudd had been surprisingly successful in portraying himself as a new prime minister instead of the same leader who was once dumped by his colleagues. "If Rudd can ram home that advantage, then Labor has got a chance," Economou said. "The task for Abbott is to try to remind people that it's Rudd, he's the leader of a party that's been in government for a long time and is really at war with itself," he added. In a major policy difference, Abbott wants to scrap both the carbon and mining taxes Labor introduced. The carbon tax on Australia's biggest polluters is AU$24.15 a metric ton of carbon dioxide, which the opposition says is too high and making Australia uncompetitive. The tax is due to be replaced in 2015 by an emissions trading scheme. Rudd has pledged to bring forward the scheme linked to the European market by a year to July 2014, substantially reducing the cost to Australians. The 30 percent mining tax on the profits of iron ore and coal miners was designed to cash in on profits from a mineral boom fueled by Chinese industrial demand, but the boom was already cooling. The tax forecast to earn AU$3 billion in its first year collected only AU$126 million after six months.