Ron Paul's Background:

Paul was an obstetrician/gynecologist before being elected to Congress in 1976.

He served as a U.S. congressman from Texas over three different periods: From 1976 to 1977 after he won a special election; from 1979 to 1985, when he left Congress to (unsuccessfully) run for the U.S. Senate; and from 1997 through the present.

In July, the 76-year-old said he would not seek re-election to Congress in 2012 so he can focus on his presidential campaign.

Rep. Paul and his wife of 54 years, Carol, have five children, including freshman U.S. Kentucky Sen. Rand Paul.

Ron Paul on the Issues:

Taxes: Paul wants to abolish the federal income tax and the Internal Revenue Service. He wants to slash $1 trillion from the federal budget. Paul would also audit and eventually abolish the Federal Reserve.

Entitlements: Paul would allow young people to opt out of Social Security and make their own investments. Though he has called Social Security unconstitutional, he thinks the program should be maintained.

Foreign policy: Paul’s isolationist foreign policy views call for vastly reducing American military spending overseas and eliminating foreign aid. He fiercely opposes the wars in Iraq and Afghanistan.

He opposes a pre-emptive strike on Iran, which he has said does not threaten U.S. national security.

Abortion: Paul opposes abortion. He has signed a pledge to appoint only people with anti-abortion views to key positions in his administration.

Immigration: Paul would recall U.S. troops from overseas and have them patrol the U.S.-Mexican border. He opposes a border fence, arguing that it would be more dangerous by keeping people in America than by keeping foreigners out.

Environment: Though Paul has backed some tax incentives for clean energy, he generally opposes federal environmental regulation. He opposes tax breaks for oil and gas companies.

Paul has previously called global warming a "hoax" and has questioned climate science.

Ron Paul's Accomplishments:

In Congress, Paul has served on the House banking committee. He currently serves on the House Committee on Financial Services and the House Committee on Foreign Affairs.

Paul has written more than ten books, including “End the Fed,” “The Revolution: A Manifesto,” and “Liberty Defined: 50 Essential Issues that Affect Our Freedom.”

Ron Paul Weaknesses/Controversies:

In the 1980s and 1990s, an organization that Paul founded as a vehicle for his libertarian views published a series of newsletters that included racially charged statements. Paul insists that he did not write or review them.

Paul’s libertarian views put him outside the Republican mainstream. His views also make it easy for opponents to paint him as extreme or radical