Romney says he opposes abortion in most cases with an exception for rape, incest, and danger to a pregnant women's health. His running mate Paul Ryan sponsored bills with Rep. Akin banning all forms of abortion and supporting "personhood" laws that define a fertilized egg as a human being and would outlaw birth control pills and In Vitro Fertilization treatments. Ryan has since softened his stance, saying Romney's policies are a step "in the right direction."

Obama also refuses to provide federal funding for abortion services in his Affordable Care Act for healthcare, but has expressed support for preserving access to legal abortion services.

"I am committed to protecting this constitutional right," Obama said on the 2011 anniversary of the Supreme Court decision legalizing abortion."I also remain committed to policies, initiatives, and programs that help prevent unintended pregnancies, support pregnant women and mothers, encourage healthy relationships, and promote adoption,"

Only a minority of American (four in 10) favor ending legalized abortion, and an even smaller percentage (one in five) think abortion should be illegal in all circumstances, even rape and incest.

Gun control

A masked gunman in July opened fire at a cinema in Aurora, Colorado, killing 12 and injuring 58. Weeks later, a gunman killed six people at a Sikh temple in Wisconsin. In just one August weekend, 37 people were wounded and nine killed in gun violence across Chicago. Even though most Americans support a constitutional right to own guns, many voters are concerned that gun violence is spiraling out of control in America.

Neither presidential candidate supports enacting new restrictions on gun control, however. This social issue runs deep into the American identity, with an organized opposition headed by the National Rifle Association who sees it as their patriotic duty to protect citizens' right to bear arms. Many Americans see guns as a way to protect their families and themselves against those who would do them harm, and an important check on the military power of the government.

President Obama has said he would work with "existing law" to curb gun violence but has not followed up on previous campaign promises to enforce registration and background checks. He has signed bills allowing guns in national parks and on the Amtrak train system. He has not pushed for a reinstatement of a ban on assault weapons.

Republican candidate Romney has taken a stronger stance against gun violence, despite being the NRA's favored candidate. Romney supported a ban on assault weapons when running for a Massachusetts Senate seat in 1994, and signed a 2004 assault-weapons ban in the state as governor. Now, as a presidential candidate, Romney has said he does not support any gun control legislation, and opposes the effort for a new assault weapons ban.

Obama and Romney seem to be playing it safe, as public opinion changes little on gun control, even after a mass shooting. A majority of Americans (54 percent) believe laws covering the sales of firearms should be made less strict, according to a Gallup poll this year.

Legalization of marijuana

During the 2012 presidential election, the candidates have avoided taking a stand on legalizing marijuana for medical use, but observers say growing public support, especially in key swing states like Colorado, could push this issue to the forefront of the campaign for the first time ever.

Some have suggested that Obama will legalize medical marijuana before the election, though the move seems unlikely. Under the Obama administration, federal raids of medical marijuana clinics in California have increased. Despite this, Obama acknowledge that legalization was "an entirely legitimate topic for debate", a far more progressive stance than any sitting president has made before.

Romney emphatically opposes any legalization of marijuana, even for medicinal use, and promised to fight legalization "tooth and nail."

"The entryway into our drug culture for our young people is marijuana," Romney said during the primary campaign. "Marijuana is the starter drug. And the idea of medical marijuana is designed to help get marijuana out into the public marketplace and ultimately lead to the legalization of marijuana overall. And in my view, that's the wrong way to go."

The author is a freelance writer living in New York City