Here's where Sen. Joe Biden, D-Del., stands on the issues.

Abortion: Biden believes that life begins at conception, opposes public funding for abortion and supports a ban on late-term abortions, but does not want to see Roe v. Wade overturned.

Climate/Energy: Biden favors legislation to reduce greenhouse gas emissions to 80 percent below 1990 levels by 2050 by imposing a cap and trade system. He favors requiring that at least 20 percent of the country’s electricity comes from renewable sources such wind, solar, biomass and geothermal. And he would seek to raise fuel economy standards so that the U.S. reaches a 40-mpg average by 2017.

Guns: In response to the shootings at Virginia Tech, Biden said, "We should not have let the assault weapons ban lapse. We should close this so-called gun show loophole. ... We have let the country down in the way in which we have not focused on mental illness."

Health: Biden wants to expand health insurance to cover all children and to make catastrophic care available for everyone. He favors allowing states to look for ways to provide universal coverage. He believes that information technology can raise efficiency, cut costs and reduce costly errors, and supports investing $1 billion a year in converting all health care systems in the country to digital medical records systems.

Immigration: Biden has voted in favor of comprehensive immigration reform, building a fence along the U.S.-Mexico border, establishing a guest working program, allowing illegal immigrants to participate in Social Security if they have paid into the system, giving guest workers a path to citizenship, and allowing more foreign workers into the U.S. for farm work. He has voted against making English the official language of the United States.

Marriage: Biden voted for the 1996 Defense of Marriage Act, which prohibits same-sex marriage under federal law. He voted against a proposed constitutional amendment banning same-sex marriage and also voted in favor of expanding the definition of hate crimes to include sexual orientation.

Taxes/Economy: "We are giving people tax breaks who don't need it,” Biden said at the July 23, 2007, Democratic debate. "The top 1 percent got an $85 billion-a-year tax break. It is not needed." In the Senate, Biden voted in favor of taking some annual tax cuts for the top 1 percent of earners. He voted against repealing the Alternative Minimum Tax, raising estate tax exemption to $5 million and permanently repealing the estate tax.

Iraq: Biden originally supported President George W. Bush on the Iraq invasion, but now says that support was a mistake. "President Bush does not have a strategy for victory in Iraq,” Biden says. "His strategy is to prevent defeat and to hand the problem off to his successor." Howqever, "We can't just pull out now. ... The truth of the matter is: If we started today, it would take one year, one year to get 160,000 troops physically out of Iraq, logistically."