US elections: Swing states control road to White House WHEN Mitt Romney picked car workers in Ohio this week as the subject of one of the final television advertisements of his presidential campaign, it was no random choice. No Republican has ever won the White House without carrying the key battleground state, and analysts predict that its 7.8 million voters will be crucial again in determining who wins Tuesday's election. With the majority of the 50 states either clearly for the Republicans or the Democrats, both candidates are concentrating their resources over the last weekend of the campaign almost exclusively in the handful of undecided states. The parties have launched a billion-dollar advertising blitz. Ohio, which has backed the winning Republican candidate in six of the last ten elections, and the triumphant Democrat in each of the other four, is receiving plenty of attention. Mr Romney and his running mate Paul Ryan were there yesterday to make their last-minute pitches to voters alongside several senior Republican figures, and president Barack Obama was planning campaign stops there today in pursuit of the state's 18 electoral college votes. "The path to the White House runs through Ohio," Dr Patrick Haney, professor of political science at the state's Miami University, told The Scotsman. It carries a large number of college votes and Ohio can go back and forth, so that puts it in the bullseye. According to the latest figures from online analyst Real Clear Politics, Mr Obama retains a 2.3 per cent advantage in Ohio, although statistically the state is a tie given opinion polls" margin of error. It is not the only state crucial to each side's hopes. Florida, Virginia, New Hampshire, Wisconsin and Michigan are also key, with several others such as Pennsylvania, North Carolina, Iowa, Colorado and Nevada on the periphery of swing status. Aside from Ohio, the jewel in the crown is Florida, which awards its victor 29 electoral college votes, more than 10 per cent of the 270 needed nationally. Politics in Florida, which supported Mr Obama in 2008 and George W Bush in each of the two previous elections, is largely split on racial and geographical grounds. The north of the state traditionally votes Republican and the south Democrat, despite the influence of Miami's sizeable Cuban-American population that leans right. That leaves the so-called I-4 corridor from Tampa and Orlando to Daytona Beach in the middle of the state to decide things, an area heavily populated with Puerto Ricans, employees from the theme park industries and what remains of the Nasa workforce from the Kennedy Space Centre and private space companies. Mr Romney has made significant ground in the Florida opinion polls in recent weeks, according to Real Clear Politics, overturning a four-point deficit to lead by 1.2. "It's hard to win the presidency and not win in Florida, and it's hard to win in Florida without winning the Hispanic vote," said Casey Klofstadt, associate professor of political science at the University of Miami in Florida. Race is also expected to play a role in the election in Virginia, whose 13 college votes went to Mr Obama in 2008. Mr Romney holds a 0.5 per cent advantage in the opinion polls but his controversial stance on immigration might not sit well with the growing number of minority voters. Virginia also has low unemployment and a low debt-to- income ratio compared to national figures, factors that might benefit the Democratic camp. Of the north-eastern states badly affected by superstorm Sandy earlier this week, only New Hampshire could be considered a true swing state whose outcome could be affected by ongoing power cuts and displacement of some residents. Women voters, who were 61 per cent in favour of Mr Obama in 2008, could again hold the key, especially given Mr Romney's strong anti-abortion stance and pledge to end funding for Planned Parenthood, the women's health organisation that provides abortions and counselling. The closeness of the results in 2000 and 2004 meant Wisconsin became a swing state, and although the Republicans have lost there in each of the last six elections, Mr Romney has hopes of capturing its ten college votes next week. Unemployment and industrial relations are prominent issues in the state of 5.7 million people, where mass protests and a walkout of Democratic politicians greeted a plan by the Republican-controlled legislature to end collective bargaining rights last year. Mr Obama holds an opinion poll lead in Wisconsin of five points, according to Real Clear Politics, the largest in any of the swing states. Yet Mr Romney, campaigning there yesterday, is not ready to concede.