It is not just the economy. From the role of government to abortion, we bring you the key issues that divide Barack Obama from Mitt Romney - as America prepares to go to the polls.

Presidential election ballot paper (getty)

Healthcare

Republicans want to repeal much of Barack Obama's affordable care act, his flagship accomplishment, which has extended healthcare provision to millions more Americans.

Mitt Romney says the state is overstepping its boundaries by mandating all citizens to purchase some kind of medical insurance or face a fine. He says he would overturn the law on day one, although he has now pledged to keep some of the most popular clauses.

Immigration

Obama tried to pass a law called the DREAM act, allowing children of illegal immigrants a path to US citizenship, which was defeated by house Republicans. However, Obama managed to bypass the defeat, under a homeland security directive effectively granting the same rights.

Romney has called for much tougher border security and suggested that immigrants should be encouraged to "self-deport". He also lent his support for tough measures which Arizona tried to introduce to crack down on illegal immigrants.

Abortion

Women's issues, specifically abortion, have been a hot political issue this election cycle, given the rise of social conservatives on the right. Things came to a head in the debate over Obama's healthcare reforms, and a move to force religious organisations to provide coverage for contraception. Obama was forced to drop the measure, amid the right wing backlash.

Conservatives, including Romney, also want to cut off funding to the women's health organisation Planned Parenthood, which provides abortion services. The Democrats have dubbed Republican attitudes on choice issues as part of a "war on women".

Social security/Medicare

The choice of Paul Ryan as Mitt Romney's running mate seems to signify a determination to slash the large proportion of federal spending on entitlements, principally social security and Medicare.

Democrats say the Republicans essentially want to privatise the system and turn it into vouchers: they say individuals would be encouraged to buy it on the private market instead.

However, Obama has failed to call a halt to payroll tax cuts that were designed to help fund future social security payouts - critics say this has left a $100bn shortfall.

Economy

This is by far and away the biggest election issue, from the $16tr deficit to the state of the banking and financial system. Rancour between the two parties over stimulus spending versus sweeping budget cuts have caused gridlock and political stalemate in congress, which has still failed to pass a budget for 2012.

Obama signed into law a $768bn package of stimulus spending and tax cuts, to help boost the economy. He wants to extend the Bush era tax cuts for households making less than $250,000 a year, but wants to increase the tax rate paid by the wealthiest.

Republicans want to prioritise slashing the deficit, mostly by sweeping cuts in federal and state spending, along with other tax cuts they say will prompt more private investment in the economy.

Role of government

The widening gap between Democrats and Republicans is best illustrated by their differences over the role of government. Democrats see it as an essential safety net for those unable to help themselves, and believe strongly in regulation, building infrastructure, and helping to boost employment.

Obama’s healthcare reforms have increased the state's role in providing healthcare, and he has also used federal funds to bail out the auto industry and to protect the economy from bank failures.

Romney wants to repeal the regulations on Wall Street and banks imposed in 2010, wants fewer federal employees, and lower taxes across the board. He has also said the government should not be involved with issues like same-sex marriage or abortion limits.

Foreign policy

President Obama has ended US military operations in Iraq and is working towards a troop withdrawal from Afghanistan by 2014. His major success came with the death of Osama bin Laden, although the violent uprisings in Libya and Syria continue to present further challenges.

Republicans have accused him of weakness abroad, of failing to lead the international response to Syria and Iran, and of kowtowing to economic pressure from China.

Many of Romney's foreign policy pledges are not substantially different, although he has said it is "unacceptable" for Iran to possess a nuclear weapon and has refused to rule out a military option.