Final battle for the White House begins Barack Obama and Mitt Romney are set for a frenetic final day of campaigning as they seek to energise the electorate in key swing states before Tuesday's US presidential election, with the fierce battle involving rival rallies in Ohio. Mr Obama campaigns in Wisconsin, Ohio, Iowa, while Mr Romney will start in Florida then travel to Virginia, Ohio and New Hampshire. The president will end up in his home town of Chicago on Monday night where he will await Tuesday's results, while Mr Romney will be at home in Boston. They blitzed four and five states respectively on Sunday in the final dash to election day. "We know what change looks like, and what he's selling ain't it," Mr Obama, referring to his rival, told an estimated 20,000 people who waited in the freezing cold for a late-night rally in Aurora, Colorado, on Sunday night. Changing the facts when they're not convenient to your own campaign, well that's not change. It was the 13th time the president had visited the state this year. Mr Obama compared the Aurora cinema shooting in July, in which 12 people were killed, to the hurricane that hit New Jersey and New York last week. "Just as you begin to heal as a community, we're going to help our friends on the East Coast heal as well," he said. We're going to walk with them every step of the way. No matter how bad a storm is, we come back. No matter how tough times are, we will thrive. Meanwhile, about 20,000 people braved the cold in Morrisville, Pennsylvania, to see Mr Romney visit the state for the first time in six weeks. "We're taking back the White House because we're going to win Pennsylvania," Mr Romney told the crowd. We're Americans. We can do anything," he said. The only thing that stands between us and some of the best years we've known is lack of leadership. And that's why we have elections. Both Mr Obama and Mr Romney are drawing their largest crowds of the election, at the end of a campaign that has cost an estimated $6bn. Despite the huge amount that has been spent on advertising, the polls suggest that the final result may come down to the work done for free by networks of volunteers following their own microcosmic battle plans to mobilise potential supporters in individual wards and counties to eke out every last vote. Polls overnight indicated that Mr Obama is still holding a slight but significant edge in states such as Ohio, Iowa and Wisconsin. The outcome of the election will turn on the ability of his Republican challenger to win some or all of those states while also closing the deal in Virginia, Florida and other places he will campaign, and where polls show him with a small advantage. The punishing schedule reflects the unpredictability of a race where pollsters are also throwing their all into a final effort to predict the outcome of what is likely to be the closest race since 2000. National polls have shown Mr Obama with a modest lead or put the rivals neck-and-neck in the race. The Pew Research Center poll released on Sunday gave Mr Obama the edge with 48 per cent of the vote over Mr Romney's 45 per cent. According to the survey, the incumbent has gained a small advantage compared with the previous poll before last week's hurricane when the two were deadlocked, suggesting his handling of Sandy's fallout has helped. The Real Clear Politics aggregate of national polls on Monday put Mr Obama a whisker ahead, with a 0.5 point margin over his rival.