"Tom Coburn is a maverick and tailor-made for the Senate because he is willing to stand up and stop everything on principle," says University of Oklahoma political science Professor Keith Gaddie.

"In a debate back before the GOP primary, Coburn was asked about the backlog of unconfirmed judicial appointments in the Senate. His response 'When I get to the Senate, if those judicial appointments are unfilled, I will see to it that nothing moves and nothing happens in the U.S. Senate until those appointments are confirmed,'" Gaddie recalls.

The family physician and former businessman has a reputation for speaking his mind. During the six years he represented Oklahoma's 2nd Congressional District in the U.S. House of Representatives, Coburn was adamant in his anti-abortion stance, attaching anti-abortion riders to appropriations bills. He also founded and served as co-chairman of the congressional Family Caucus, a group of about 60 members of the House.

Coburn held the 2nd District seat -- the same one currently held by his senatorial opponent Brad Carson -- from 1995-2001. He was the first Republican to hold the seat for consecutive terms in this rural and Democratic district, and he retired when he said he would, after three terms.

Elected in the Republican revolution of 1994, he helped lead a revolt against its chief architect and then-GOP House Speaker Newt Gingrich. Coburn was a member of the Commerce Committee where he vice-chaired the Subcommittee on Health and Environment, and sat on the Energy and Power, and Oversight and Investigations subcommittees.

Prior to being elected to the U.S. House of Representatives in 1994, Coburn had never held an elected position. He was raised in Muskogee, Okla. and graduated from Oklahoma State University with a degree in accounting. He was also president of the College of Business Student Council.

From 1970-78, Coburn was the manufacturing manager at the Ophthalmic Division of Coburn Optical Industries in Colonial Heights, Va.

When the family sold the business, the Oklahoman returned home and decided to return to school. Coburn was president of his class at the University of Oklahoma Medical School and graduated in 1983. He did his internship in general surgery at Saint Anthony's Hospital in Oklahoma City and family practice residency at the University of Arkansas, Fort Smith.

Coburn's family practice in Muskogee serves more than 15,000 patients and he has personally delivered almost 4,000 babies, according to his Web site. He and his wife Carolyn have three children.

While in Congress, Coburn declined his government pension and health care benefits and supported legislation to limit perks to all members of Congress.

He helped draft the partial birth abortion ban signed into law in 2003 and authored a bill encouraging the testing of infants for HIV. According to his Web site, The Wall Street Journal said that: "In 10 long years of AIDS politics and funding, this is actually the first legislation to pass in this country that will rescue babies."

Within his first year in office, the National Republican Congressional Committee singled out Coburn's office as one of the "most efficient" of the 73 new Republicans elected in 1994, an assessment based on how well the staff handled duties such as legislation and constituent services.

Coburn was also known as a budget hawk. His Web site quotes a 1999 USA Today article that said he "brought the House to a virtual standstill by threatening to attach 130 amendments to an agriculture appropriations bill that he thought cost too much. Since then, he's almost single-handedly forced nearly $1 billion in cuts from the first seven spending bills the House has passed for the next fiscal year."

Near the end of 2001, Coburn was chosen to co-chair the President's Advisory Council on HIV/AIDS, a position he still holds.

Coburn garnered the Republican nomination in a bruising primary that included accusations of double-crosses and shady land dealings. Former Oklahoma City Mayor Kirk Humphreys started out as the favorite, with endorsements from Oklahoma's other senator, Jim Inhofe, former Rep. J.C. Watts and other party leaders.

The campaign turned ugly when a third candidate, Bob Anthony, vice chairman of the Oklahoma Corporation Commission, ran a series of ads in the days prior to the primary questioning real estate sales Humphreys made years ago. Humphreys called Anthony a "cut and slash" guy.

"Tom Coburn is a wonderful man, but Bob did his dirty work for him," Humphreys said. "Coburn would be hard to beat on a level playing field, but it was not a level playing field."

On primary night, Coburn urged Republicans to unite behind his candidacy.

-- Compiled for the Online NewsHour by Leah Clapman