Ohio is one of the most important states in this election, and both parties are fighting tooth and nail: not just on the doorsteps, but in the courtrooms as well, mobilising armies of lawyers and wrestling for every angle and advantage they can. Sometimes these tactics can get dirty. The Republican state government of Ohio, and its Secretary of State Jon Husted, knows this well. Democrats accuse it of disenfranchising poorer and minority voting with two separate actions: a controversial voter ID law and a series of complex changes in the hours and availability of early voting.

Early voting begins on October 2, allowing people to cast their vote in person at any time in the five weeks from then until the election. How many people use this option is dependent on several factors, especially the opening hours of the polling stations, which have gone through a number of changes this year. It is a significant factor in elections: in the 2008 Presidential race in-person early voting accounted for 265,048 votes; Obama's margin of victory over McCain in Ohio was just 262,224.

Earlier this year, with almost unbelievable gall, Husted was allowing rural (Republican-run) counties to extend their planned early voting hours into the evenings and weekends, while denying the same opportunity to more industrial, poorer and urban Democrat counties. The New York Times called him out on this in August. Democrats and the Obama campaign cried foul, and Husted was forced to impose uniform hours over the whole state. Democrat campaigners now argue that the hours Husted has imposed are meagre – 8AM until 5PM for the first three weeks, then until 7PM; and only on weekdays; and closed on the the last three days before election day – and so they still discriminate against working-class and poor (and likely Democrat) voters.

An uneasy peace appeared to reign while various aspects of these rules were worked through the courts – the cases are still ongoing; this will be a very litigious campaign – but the flames of controversy were relit by Doug Preisse, chairman of the Franklin county Republican party, who was accused of racism after telling a newspaper in the state capital Columbus: “I guess I really actually feel we shouldn’t contort the voting process to accommodate the urban – read African-American – voter-turnout machine.”

Pete Gerken is the President of the board of election commissioners of Lucas county, in the north of the state. He is a Democrat. “Just in this county alone [in the 2008 Presidential election], 28,000 people voted early, 5000 of those on weekends,” he tells me. “Any redrawing of early voting hours is an attempt to suppress people's ability to vote. The majority of people who use early voting, especially those who need it to be after work or on weekends, tend to be Democrat. They're working-class, they're working people; they can only get there after work.”

Running parallel with the early voting argument is another row, about the new voter ID laws that Ohio and a number of other states have just adopted. These new laws demand that voters, who could previously present themselves at the polling station with just a utility or rent bill as identification, must now produce state-issued photo identification at the polling station. This, opponents say, discriminates heavily against minorities and the poor, who are statistically far, far less likely to have photo ID – or indeed to have heard of the new law.

“The Republican officials in the State who passed the laws are doing it under the flag of preventing voter fraud,” says Gerken. “But there hasn't been any fraud – it's a problem that doesn't exist in the state of Ohio. In the last four years there have been less than ten charges of voter fraud in the whole state. They're trying to fix a problem that doesn't exist, and trying to fix it with a jackhammer. What is happening is people are being taken out of the queue – people who don't drive, the poor, the elderly. It disenfranchises people from their right.

“It's a strategy. It's a strong strategy, and [the Republicans are] trying it in lots of states. … It flies in the face of our democratic values, and I don't think they care.”

Pennsylvania is one of the states in which the voter ID row has been loudest. Here, according to a study by Matt Baretto at the University of Washington, around an eighth of the electorate, more than a million voters, are currently without state photo identification for one reason or another; and only 34 per cent are aware of the new law. The Pennsylvania Supreme Court is currently debating the issue, and will announce its decision in the next couple of weeks. It will be big news when it does.

In Ohio, Husted - despite being ordered by a district court judge to reinstate early voting on the last three days before the election - has not yet done so; claiming that to act while the ruling is still being appealed would “futher confuse voters”. In this, he is probably right. The tooth-and-nail legal battles being fought over these issues can only further alienate voters from the process – but in a state that might come right down to the wire, to the candidates each battle is absolutely crucial. Which means, unfortunately for fans of a nice clean contest, it's going to be no-holds-barred right up until election day.

Previously in this series: How the fighting talk fizzled from Mitt Romney's party