Mitt Romney, the former governor of Massachusetts and a front-runner for the Republican presidential nomination, has faced criticism since he first ran for president in 2008 over so-called flip-flops on key issues, especially social issues like abortion, immigration and same-sex marriage. The basic question many voters want answered is simply, what does Mitt Romney believe?

Here are Romney's positions on some of the most important questions of the 2012 campaign.

ECONOMIC ISSUES

Entitlements:

Romney says he wants to reform entitlement programs like Social Security, Medicare and Medicaid to ensure long-term solvency while not reduc[ing] benefits for current seniors or break[ing] the promises they have relied upon for their economic security in retirement, according to his Web site, which calls on the federal government to publish an annual balance sheet so that Americans can understand the burden that future entitlement spending will place on our budget and economy.

Earlier this month, he outlined a more specific plan for entitlement reform. He would turn Medicaid over to the states and cap its spending to save $100 billion, and he would increase the eligibility age for Social Security by an unspecified amount. But the most dramatic changes would be to Medicare, which he would semi-privatize. Seniors would receive a fixed amount of money to buy either Medicare coverage or private insurance, which Romney says would spur competition and make Medicare less expensive for the government. He says these changes would not affect current retirees or people who are about to retire, but he did not say what the cutoff would be.

Health care:

Romney has vowed to issue an executive order on his first day in office that would start the process of overturning President Obama's health care law by direct[ing] the secretary of health and human services and all relevant federal officials to return the maximum possible authority to the states to innovate and design health care solutions that work best for them, according to his Web site.

He argues, as most Republicans do, that the only way to strengthen the country's health care system is through the free market, not through government management and regulation. He supports some regulations, such as the ban on denying insurance for people with pre-existing conditions, but decries the all-encompassing approach of Obamacare.

He wants Congress to repeal Obama's health care law, and he would replace it with several new policies. First, he would block-grant Medicaid funds to the states for them to allocate at their discretion, taking the public health insurance program out of the federal government's purview. He would also extend the tax deduction for purchasing insurance through an employer to apply to people who buy their own insurance and let individuals choose whether to keep their employer-based insurance or switch, and he would expand health savings accounts, which allow people to put money aside for health care without paying taxes on deposits.

Job creation:

One of the main components of Romney's job creation plan is lowering individual and corporate tax rates and eliminating the estate tax and capital gains tax. He wants to cut regulations that he believes have stifled economic growth, including the Obama health care law and the Dodd-Frank financial regulatory law, and he has promised to review all Obama-era regulations and eliminate any that unduly burden the economy and job creation. He has also proposed a zero-dollar regulatory cap, which would force any government agency that wanted to create a new regulation to offset the cost by loosening existing regulations.

He argues that increased free trade will lead to job creation, so he has pledged to sign the Colombia, Panama and South Korea Free Trade Agreements. He would also delegate responsibility for worker retraining programs from the federal government to the states and pursue immigration policies that would attract and retain job creators from wherever they come by expediting the path to citizenship for student visa holders who graduate with a degree in math, science or engineering.

Taxes:

Romney has pledged to submit a bill to Congress on his first day in office that would reduce the maximum corporate income tax rate from 35 percent to 25 percent. He also wants to eliminate the estate tax and taxes on capital gains, interest and dividends, which he says will allow taxation to become an instrument for promoting economic growth.

In the long term, he has proposed a conservative overhaul that applies lower and flatter rates to a broader tax base, although, unlike some of his opponents, he has not presented a detailed plan with specific rates and changes. Eventually, he wants to make the marginal tax rate for corporations less than 25 percent and reduce individual rates by broadening the tax base, or taxing more individuals and corporations.

Lastly, he wants to transition from a worldwide to a territorial corporate tax system, meaning that multinational corporations would only pay taxes on income earned in the United States. The idea is to encourage corporations to take international profits and invest them domestically, rather than keeping those profits abroad in order to avoid taxes. In designing a territorial system, though, Romney says Congress would have to avoid creating incentives for corporations to outsource in order to minimize the profits they earn inside the United States.

FOREIGN POLICY

Afghanistan:

Romney has pledged, in his first 100 days in office, to open a full inter-agency review of the United States' military involvement in Afghanistan in order to determine the level required to secure our gains and to train Afghan forces to the point where they can protect the sovereignty of Afghanistan on their own, according to his Web site. He says he would not set a timeline for withdrawing troops, because any withdrawal would depend on conditions on the ground as assessed by our military commanders.

His Web site also emphasizes that the United States' military efforts in Afghanistan must be coupled with actions on the part of the Afghan government, including President Hamid Karzai, to eliminate corruption within the government and combat the narcotics trade that sustains the Taliban insurgents.

Iran:

Romney has taken a hard line on the issue of Iran, emphasizing at a recent Republican debate that he would authorize the use of military force if necessary to prevent Iran from developing a nuclear weapon. He characterized it as a last resort if diplomacy failed, but his Web site says that within his first 100 days in office, he would make clear that the military option is on the table by ordering the regular presence of an aircraft carrier task force in both the Eastern Mediterranean and the Persian Gulf region. His strategy is to demonstrate strength and resolve, because he believes that the best ally world peace has ever known is a strong America.

He wants to improve intelligence-sharing and military coordination with Israel to prepare for the possibility of military action against Iran, and his Web site also says that he commits to the on-time completion of a fully capable missile defense system in Eastern Europe. He would also encourage the development of a more powerful opposition within Iran by improving the flow of information to the Iranian people about its own government's repressive activities, although he does not specify how he would go about that.

In terms of diplomatic options, Romney has called for harsher economic sanctions on Iran and stricter enforcement of existing laws that ban commerce between the United States and Iran. He also supports efforts to indict Iranian President Mahmoud Ahmadinejad for incitement to genocide under the United Nations' Genocide Convention.

Iraq:

Romney opposed President Obama's decision to withdraw American troops from Iraq, calling it an astonishing failure to secure an orderly transition and a threat to the victories that were won through the blood and sacrifice of thousands of American men and women. He has called on Obama to make public the recommendations he received from military commanders on the ground.

He has not proposed specific policies of his own. His Web site says only, U.S. military and diplomatic personnel have made stunning gains in Iraq. But in light of [the] reported drawdown of troops to levels far below what military commanders recommend, it is impossible to forecast what conditions in Iraq will confront the next American president in January 2013. Mitt Romney will enter office seeking to use the broad array of our foreign-policy tools -- diplomatic, economic and military -- to establish a lasting relationship with Iraq and guarantee that Baghdad remains a solid partner in a volatile and strategically vital region.

SOCIAL ISSUES

Abortion:

Romney's position on abortion has been a matter of substantial confusion, because he has made various statements and pursued various policies over the years. In 1994, when running for a U.S. Senate seat in Massachusetts, he was strongly pro-choice, supporting federal funding for abortion in at least some cases and saying famously in a debate with Edward Kennedy that he supported legalized abortion because a relative of his had died from an illegal abortion.

In 2001, when he was organizing the 2002 Winter Olympic Games in Salt Lake City and there was speculation that he might run for office in Utah, he wrote a letter to the editor in which he said, I do not wish to be labeled pro-choice. But when he launched his campaign for the Massachusetts governorship, he said he was, in fact, pro-choice.

Finally, in 2005, when he began talking about a 2008 presidential run, he wrote in a Boston Globe op-ed, as an explanation of why he vetoed a contraception bill, I am pro-life. I believe that abortion is the wrong choice except in cases of incest, rape, and to save the life of the mother. The following year, he reconciled his positions by saying that he used to be pro-choice, but was converted in 2004 when a stem-cell researcher told him, Look, you don't have to think about this stem cell research as a moral issue, because we kill the embryos after 14 days.

Today, he continues to characterize himself as pro-life, but his Web site does not mention abortion policies and it is not a subject he frequently discusses on the campaign trail.

Education:

Romney supports a somewhat larger federal role in the education system than his opponents do. When he ran for Senate in 1994, he proposed eliminating the Department of Education -- something Ron Paul advocates today -- but, he said in a 2007 debate, As I've been a governor and seen the impact that the federal government can have, holding down the interest of the teachers' unions and instead putting the interests of the kids and the parents and the teachers first, I see that the Department of Education can actually make a difference. He has also said he would keep the No Child Left Behind Act in place. However, he does want to reduce the federal role from its current state.

He supports school vouchers, merit-based scholarships and more charter schools to increase parents' and students' choices, and he believes teachers and schools should be assessed based on their students' performance for greater accountability. He does not support the inclusion of creationism in science curriculums, but he has called for a greater emphasis on family values and has spoken out against sex education for very young children. He has also been very critical of teachers' unions, writing in his book No Apology, It is not the unions' job to fight for our children. That job is our job, and it's the task of the people we elect to represent us. Our elected representatives' role is to sit across the table from the unions and bargain in good faith in the interest of children and parents. But the teachers' unions long ago discovered that they could wield influence -- and, in some cases, overwhelming influence -- over the selection of our representatives on school boards and in state legislatures.

Gay marriage:

Romney's positions on same-sex marriage, as with his positions on abortion, have not always been consistent. He opposes same-sex marriage now, and back in August, he joined Michele Bachmann and Rick Santorum in signing the National Organization for Marriage's pledge to, among other things, support a constitutional amendment that would define marriage as between a man and a woman. He also opposed the repeal of the military's don't ask, don't tell policy earlier this year.

In 1994, though, in a letter he sent during his unsuccessful campaign for a U.S. Senate seat in Massachusetts, Romney wrote that he would be a stronger advocate for gay rights than his Democratic opponent, Edward Kennedy. He said that Massachusetts must make equality for gays and lesbians a mainstream concern and that he believed gays should be allowed to serve openly in the military.

He has acknowledged the letter on the campaign trail but says his positions are firm now. Governor Romney believes Americans should be respectful of all people, a spokesman told The New York Times. However, over the past four years as governor, Mitt Romney has not advocated or supported any change in the military's policies and he has not implemented new or special rights in this area. The spokesman added that Romney had never supported same-sex marriage.

Immigration:

In 2007, Romney told the Lowell Sun that, while he favored strict policies against illegal immigration, he did not want to deport every person who was here illegally. I don't believe in rounding up 11 million people and forcing them at gunpoint from our country, he said. With these 11 million people, let's have them registered, know who they are. Those who've been arrested or convicted of crimes shouldn't be here. Those that are paying taxes and not taking government benefits should begin a process toward application for citizenship, as they would from their home country. He reiterated that position in an appearance on Meet the Press, saying, The 12 million or so that are here illegally should be able to stay, sign up for permanent residency or citizenship, but they should not be given a special pathway, a special guarantee that all of them get to stay here for the rest of their lives merely by virtue of having come here illegally.

This is similar in many respects to the policies supported by President Obama, who recently instructed the Department of Homeland Security to focus on deporting illegal immigrants with criminal convictions. Today, however, Romney holds a much harder line on immigration.

He criticized Newt Gingrich at a Republican debate on Tuesday when Gingrich said he would not support deporting illegal immigrants who have been in the United States for years and have families here. Romney disparagingly called that a new doorway to amnesty, and he accused Gingrich of promoting a policy that would allow illegal immigrants to jump ahead of people who have waited for years to enter the U.S. legally. The only route to citizenship that he would support for illegal immigrants, he said, consists of going to their home country, applying for citizenship or permanent residency just like everybody else, and getting back in the line. His spokesman, Eric Fehrnstrom, told The Washington Examiner that Romney would allow no in-state tuition, no benefits of any kind, no employment. You put in place an employment verification system with penalties for employers that hire illegals, that will shut off access to the job market, and they will self-retreat.