Abortion

Baldwin: Supports overturning Roe v. Wade and stripping the appellate jurisdiction of the Supreme Court in all cases of abortion. Would "deny funds to protect abortion clinics."

Obama: Favors abortion rights. Opposes any constitutional amendment to overturn the Supreme Court's decision in Roe v. Wade.

McKinney: Supports "full reproductive rights for women," including "morning after" medication and abortion.

Nadar: Supports access to safe and legal abortions; opposes a constitutional amendment banning abortion.

Barr: The Libertarian Party position is that government should stay out of the matter of abortion, leaving the question to individuals.

McCain: Has voted for abortion restrictions permissible under Roe v. Wade and now says he would seek to overturn that guarantee of abortion rights. Would not seek constitutional amendment to ban abortion.

Afghanistan

Baldwin: The Constitution Party's stance is that the United States should withdraw from the U.N. and NATO and bring home our overseas forces.

Obama: Would add about 7,000 troops to the U.S. force of 36,000, bringing the reinforcements from Iraq. Has threatened unilateral attack on high-value terrorist targets in Pakistan "if Pakistan cannot or will not act" against them.

McKinney: Wants "an end to all wars and occupations by U.S. forces, including in Iraq and Afghanistan. We need an immediate cessation of funding for war."

Nader: Cut the military budget to a level needed to protect the United States.

Barr: "The situation in Afghanistan is deteriorating badly." Says U.S. law enforcement and military efforts should focus on terrorists who have targeted Americans, not on "unnecessary wars and interventions, such as in Iraq."

McCain: Favors unspecified boost in U.S. forces.

Death Penalty

Baldwin: Says states have the right to oppose the death penalty in "appropriate circumstances"; the Supreme Court should not interfere.

Obama: Supports death penalty for crimes for which the "community is justified in expressing the full measure of its outrage."

McKinney: Says the death penalty is based on race and class and should be replaced with life imprisonment.

Nader: Says the death penalty does not deter crime and is discriminatory. Opposed 1996 expansion of federal death penalty.

Barr: Signed 1994 Contract With America calling for an effective death penalty; voted to make death penalty appeals harder.

McCain: Has supported expansion of the federal death penalty and limits on appeals.

Education

Baldwin: Favors disbanding the Department of Education and repealing all federal legislation related to education. Wants tax relief for homeschooling and private and religious schools.

Obama: Would encourage, but not mandate, universal pre-kindergarten. Tie teacher pay raises to test scores. Overhaul No Child Left Behind law to better measure student progress, make room for non-core subjects and be less punitive toward failing schools.

McKinney: Favors more funding for education. Says No Child Left Behind is aimed at dismantling public education. Wants free higher education for all.

Nader: Wants to abandon standardized testing and shift core curriculum to focus on civic skills. Says greater investment in education will reduce poverty.

Barr: Says control of education should shift from government to parents. Would abolish the Department of Education and end federal grants and regulations.

McCain: Favors parental choice of schools, including vouchers for private schools when approved by local officials, and right of parents to choose home-schooling. More money for community college education.

Energy

Baldwin: Favors drilling in Alaska and the Gulf of Mexico. Wants to build more oil refineries and more nuclear power plants. "There is absolutely no reason for us to be dependent on OPEC."

Obama: Would consider limited increase in offshore drilling. Opposes drilling in Arctic reserve. Proposes windfall-profits tax on largest oil companies to pay for energy rebate of up to $1,000. Opposed suspending federal gas tax.

McKinney: Opposes drilling in Alaska; voted to maintain a moratorium on offshore drilling. Instead would fund development of sustainable energy sources. Wants the U.S. to be nuclear-free.

Nader: Wants to end subsidies of "entrenched oil, nuclear and coal interests." Opposes subsidies for corn ethanol. Calls for investment in sustainable sources such as wind and solar energy.

Barr: Allow drilling in Alaska and the Outer Continental Shelf. Says the federal government "should eliminate all special privileges for the production of politically favored fuels, such as ethanol."

McCain: Favors increased offshore drilling and federal money to help build 45 nuclear power reactors by 2030. Opposes drilling in Arctic National Wildlife Refuge. Proposed suspending federal gasoline tax, but idea got no traction.

Gay Marriage

Baldwin: Opposes constitutional amendment to define marriage. Believes marriage should be between a man and a woman.

Obama: Opposes constitutional amendment to ban it. Backs civil unions; says states should decide about marriage. Now supports repeal of Defense of Marriage Act, which denies federal recognition of same-sex marriages.

McKinney: Was rated as a gay rights supporter by the Human Rights Campaign while in Congress. The Green Party platform supports gay marriage.

Nader: Supports legalizing gay marriage and providing full, equal rights for homosexuals.

Barr: Says the federal government should not define marriage and that the decision on whether to recognize same-sex unions should be made by each state.

McCain: Opposes constitutional amendment to ban it. Says same-sex couples should be allowed to enter into legal agreements for insurance and similar benefits, and states should decide about marriage.

Global Warming

Baldwin: Opposes federally mandated increase in fuel-efficiency standards. Says humans are no more responsible for climate change now than they have been throughout history.

Obama: Wants 10-year, $150 billion program to produce "climate-friendly" energy supplies that he'd pay for with a carbon auction requiring businesses to bid competitively for the right to pollute. Backs tougher fuel-efficiency standards.

McKinney: Voted in 2000 to implement the Kyoto Protocol to reduce carbon emissions. Says the United States should be carbon-free. Supports increase in fuel-efficiency standards.

Nader: Proposes $50 per-ton carbon dioxide emission tax with a goal of cutting U.S. emissions to at least 80 percent below 1990 levels by 2050.

Barr: Voted against implementing the Kyoto Protocol in 2000. Opposes tougher fuel-efficiency standards. Says human beings are not responsible for global climate change.

McCain: Broke with President Bush on global warming. Led Senate effort to cap greenhouse gas emissions; favors tougher fuel-efficiency standards. Favors plan that would see greenhouse gas emissions cut by 60 percent by 2050.

Gun Control

Baldwin: Opposes gun control; says Second Amendment preserves liberty. Opposes registration of guns and ammunition.

Obama: Voted to leave gun-makers and dealers open to lawsuits. As Illinois state lawmaker, backed ban on all semiautomatic weapons and tighter state restrictions on firearms.

McKinney: Voted against requiring background checks at gun shows.

Nader: Supports trigger locks, licenses for gun owners and bans on certain weapons. Says firearms laws should protect both gun victims and law-abiding citizens who use guns.

Barr: Opposes any law "requiring registration of, or restricting the ownership, manufacture, or transfer or sale of firearms or ammunition to law-abiding citizens."

McCain: Voted against ban on assault-type weapons but favors requiring background checks at gun shows. Voted to shield gun-makers and dealers from civil suits.

Health Care

Baldwin: Opposes government regulation and subsidies of health care. Calls for "freedom of choice of practitioner and treatment." Says health care providers should be accountable to patients, not insurers, politicians or HMOs. Opposes government subsidies for HMOs. Opposes forced vaccinations.

Obama: Wants mandatory coverage for children, no mandate for adults. Aims for universal coverage by requiring employers to share costs of insuring workers and by offering coverage similar to that in plan for federal employees. Says package would cost up to $65 billion a year. Would raise taxes on wealthier families to pay the cost.

McKinney: Supports single-payer universal health care. Supports "an understandable and cost-efficient prescription drug benefit to all Americans who need it. I am against any form of health care rationing or the use of a voucher-based system of health insurance."

Nader: Supports single-payer universal health care: "A single-payer health plan, where the government finances health care but keeps the delivery of health care to private nonprofits and allows free choice of doctors and hospitals for patients." In 2000, called for a 3.5 percent payroll levy on employers and a tax on stock transactions to pay for it.

Barr: Calls for reform of health care policy based on "consumer-oriented health care." Opposes socialized medicine. Says Medicare and Medicaid have become financially unsustainable and should change to emphasize patient choice and focus on the truly needy. Would end regulations that mandate insurance coverage.

McCain: Calls for $2,500 refundable tax credit for individuals, $5,000 for families, to make health insurance more affordable. No mandate for universal coverage. In gaining the tax credit, workers could not deduct the portion of their workplace health insurance paid by their employers.

Immigration

Baldwin: Has said he would use whatever force is necessary to secure borders and supports a fence. He supports no plan that would make a path to citizenship and would end birthright citizenship for children of illegal immigrants.

Obama: Voted for 2006 bill offering legal status to illegal immigrants subject to conditions, including English proficiency and payment of back taxes and fines. Voted for border fence.

McKinney: Voted yes in 2001 on extending immigrant residency rules. Voted against building a fence along the U.S. border.

Nader: Wants better enforcement of the law barring employers from hiring illegal immigrants; supports creating a guest worker program and amnesty for those already in the country.

Barr: Wants the border secured and an end to government benefits and services for illegal immigrants, including education of children of immigrants and health care; wants to "reconsider" the policy of birthright citizenship.

McCain: Sponsored 2006 bill that would have allowed illegal immigrants to stay in the U.S., work and apply to become legal residents. Now says he would secure the border first. Supports border fence.

Iran

Baldwin: Has said the nation is not an imminent threat to the United States.

Obama: Says direct diplomacy with Iranian leaders would give the U.S. more credibility to press for tougher international sanctions. Says he would intensify diplomatic pressure on Tehran before Israel feels the need to take unilateral military action against Iranian nuclear facilities.

McKinney: Would support opening diplomatic relations with Iran; wants to stop transfer of weapons to Israel.

Nader: Believes the U.S. must stop "saber rattling" and take up Iran's 2003 proposal to negotiate all outstanding issues between the two nations.

Barr: Would support opening diplomatic relations with Iran, saying "any nonproliferation strategy must begin with diplomacy and include a willingness to address the other side."

McCain: Favors tougher sanctions, opposes direct high-level talks with President Mahmoud Ahmadinejad.

Iraq

Baldwin: Opposes the war; would begin to withdraw troops immediately after taking office. Wants the U.S. to stay out of other nations' "internal affairs."

Obama: Spoke against war at start, opposed troop increase. Voted against one major military spending bill in May 2007; otherwise voted in favor of money to support the war. Says his plan would complete withdrawal of combat troops in 16 months.

McKinney: Wants "an end to all wars and occupations by U.S. forces, including in Iraq and Afghanistan. We need an immediate cessation of funding for war."

Nader: Would withdraw troops within six months of taking office.

Barr: Opposes unilateral use of force, saying "our national defense policy must renew a commitment to nonintervention." Wants a timetable for the withdrawal of all U.S. troops in Iraq.

McCain: Opposes scheduling a troop withdrawal, saying latest strategy is succeeding. Supported decision to go to war, but was early critic of the manner in which administration prosecuted it. Was key backer of the troop increase. Willing to have permanent U.S. peacekeeping forces in Iraq.

Social Security

Baldwin: Wants to phase out Social Security entirely.

Obama: Would raise payroll tax on wealthiest by applying it to portion of income over $250,000. Currently, payroll tax is applied to income up to $102,000. Rules out raising the retirement age for benefits.

McKinney: Supported legislation saying that any budget surplus cannot be spent until the solvency of Social Security is guaranteed; voted to reduce the amount of benefits that are taxable.

Nader: "The idea that Social Security is going to run out of money is simply nonsense," he said in 2000, adding that the program has an "extremely solid" base. Does not support privatization.

Barr: Wants to privatize Social Security through personal Social Security Accounts. Supports raising the earnings cap.

McCain: "Nothing's off the table" when it comes to saving Social Security.

Taxes

Baldwin: Wants to end income taxes by overturning the 16th Amendment. Would put an end to the "death tax" and property tax and put into place a 10 percent tax on all imports. No national sales tax.

Obama: Raise income taxes on wealthiest and their capital gains and dividends taxes. Raise corporate taxes. $80 billion in tax breaks mainly for poor workers and elderly, including tripling Earned Income Tax Credit for minimum-wage workers and higher credit for larger families.

McKinney: Supports an increase in taxes for the wealthiest Americans; supports tax cuts for middle-class families; opposes elimination of the Alternative Minimum Tax and the "death tax."

Nader: Says a fundamental reappraisal of tax laws is needed -- taxes should apply first to behavior and conditions we favor least, such as alcohol and tobacco, pollution, speculation, gambling and extreme luxuries, and pinch basics such as work or food least.

Barr: Supports the Fair Tax, which would adopt a national sales tax, replacing the IRS and all federal income taxes and payroll taxes. To do this, he would work to repeal the 16th Amendment. Supports an amendment that would require the president and Congress to balance the budget each year.

McCain: Pledged not to raise taxes, then equivocated, saying nothing can be ruled out in negotiating compromises to keep Social Security solvent. Twice opposed Mr. Bush's tax cuts; now says they should be permanent. Proposes cutting corporate tax rate to 25 percent. Promises balance budget in first term.