Sen. Jean Carnahan is a straight-shooter. Literally. During a campaign stop at a farm in Missouri's bootheel, the 68-year-old freshman senator participated in a skeet shooting competition, slinging a 20-gauge shotgun and hitting nine of 15 clay pigeon targets.

Although it was the first time Carnahan has fired a gun in public since becoming a U.S. senator, she says she's no shooting novice. On the campaign trail, she mentions she won a sharpshooter's medal in college and once out-shot her security detail, the St. Louis Post-Dispatch reports. Nonetheless, Carnahan, has voted in favor of background checks on prospective gun-buyers and a Congressional ban on assault weapons, and has fought Missouri state legislation allowing the carrying of concealed weapons. But her split position on guns is not what makes Jean Carnahan's story unusual.

She's a 40-year veteran of the political campaign trail, but before this year's primaries had never appeared on a ballot herself. Born in 1933 during the Great Depression to a plumber father and hairdresser mother in Southeast Washington D.C.'s Anacostia area, she eventually grew to live in the Missouri governor's mansion with her politician husband Mel Carnahan, whom she married in 1954, when she was only 20.

And although she had never before held political office, Jean Carnahan is one of a handful of senators that pollsters are watching carefully, since her political survival is crucial to a Senate Democratic leadership hanging by a single-vote majority.

Jean and Mel Carnahan settled in the town of Rolla, Missouri, where Mel, also a Democrat, began to build a political career, first as a municipal judge in 1960, then as a state representative. After leaving the state house for a law practice in 1967, Mel Carnahan re-entered state politics in 1980 with a successful bid for state treasurer. In succeeding years, he'd rise up the state's ranks, finally becoming governor in 1993 -- a post he held until the state's term limits forced him out eight years later.

With the end of his term set for 2001, Carnahan in 2000 mounted a challenge against Republican Sen. John Ashcroft -- a bitterly fought race that was one of 2000's most-watched campaign slugfests. All that changed on Oct. 17, 2000, when Mel Carnahan died in a plane crash with the couple's son, Randy, and campaign adviser Chris Sifford just weeks ahead of the Nov. 7 election.

With the state's ballots already printed, Mel Carnahan remained on the ticket, and acting Gov. Roger Wilson, also a Democrat, announced he intended to nominate Jean Carnahan to fill the seat should her husband win the race. Missouri voters handed Mel Carnahan a posthumous victory, with the late governor picking up 51 percent of the vote to Ashcroft's 48 percent.

Jean Carnahan was inaugurated in her husband's place on Jan. 3, 2001. In her two years in the Senate, Carnahan participated in several key votes, although she did not always line up behind her party's leadership. For example, she was one of 12 Senate Democrats to support President Bush's $1.3 trillion tax cut. Meanwhile, she was an original co-sponsor of the Senate's version of the Patients Bill of Rights, played a key role in convincing the Senate to approve the TWA-American airlines merger - a move she said would benefit Missourians - and secured government disaster relief for Missouri farmers.

Most troublesome to the Carnahan camp, political analyst Charlie Cook wrote in a July column, were criticisms that Carnahan still hadn't mastered the legislative process and may not be up for the job. "As harsh as this may sound," Cook wrote, "it's fair to question someone who has never served in elective office and is appointed to a job as big as U.S. Senator" In the tightly contested race to finish her late husband's term, Carnahan faces another familiar face in Missouri politics, former Congressman Jim Talent. Given Missouri's reputation as an electoral toss-up, Carnahan's future may remain foggy until election day.

--By Greg Barber, Online NewsHour