Barnes has gone on to an adult life largely spent in public office. Now, eight years after voters turned him out as governor after a single term, the 62-year-old Democrat is angling for a comeback.
To win, Barnes must run not just against GOP opponent Nathan Deal but against the national Democratic Party establishment and President Obama, whose approval ratings in Georgia trail the national average.
With his rumpled hair and folksy drawl, Barnes can turn on the backslapping Southern charm. He's also a shrewd trial lawyer and politician. And while he calls himself a "poor ol' country lawyer," Barnes has a net worth of $16.6 million.
Barnes might have grown up on a modest dairy farm, but these days he lives in a sprawling Victorian home in Marietta. He worked six days a week and Sundays were for church, so there wasn't much time for family travel. When he got out of his father's pickup truck at the University of Georgia in the 1960s, it was his first time in Athens.
Barnes blazed through his undergraduate studies and went straight into the University of Georgia Law School.
In college he was a Republican, saying that then-Gov. Lester Maddox's hard-line segregationist views turned him off to the Democratic Party.
After earning his law degree, Barnes returned to Cobb County and took a job in the Cobb County District Attorney's Office. He married his first love, Marie, a schoolteacher.
Barnes was elected to the state Senate in 1974 at 26, the youngest person to serve in the chamber. Along the way, he also set up a thriving private law practice.
Barnes and his brother, Ray, opened Georgia State Bank. It was eventually sold to Alabama National Bancorp and then to RBC. The shares from those sales have added millions of dollars to Barnes' bottom line.
In 1990, Barnes made his first run at the governor's mansion, jumping into the Democratic primary against then-Lt. Gov. Zell Miller and former Atlanta Mayor Andrew Young. He finished third, and Miller went on to be elected governor.
Barnes returned to the state Capitol in 1992 and served three terms, this time in the state House. In 1998, he claimed the governorship, defeating Secretary of State Lewis Massey in a primary and Republican businessman Guy Millner in the general election.
As governor, Barnes pushed an ambitious agenda. His full-throttle approach was admired by those who respected his vision. Others saw arrogance and gave him the nickname "King Roy."
He passed a sweeping education reform bill, was able to shrink the racially charged Confederate battle emblem on the state flag and muscled through a tough predatory lending bill.
Barnes seemed an easy bet for re-election in 2002, but anger from teachers and rural white voters upset with changes to the state flag helped lead to an upset victory by Republican Sonny Perdue.
For six months after losing, Barnes worked for Atlanta Legal Aid, where he represented poor clients and worked on consumer issues.
He then set up a law practice in Marietta with his daughter, Alison, and son-in-law. Barnes has handled a few high-profile cases that have helped keep his name in the news, fighting a state voter identification law that requires voters to show a photo ID at the polls. Opponents say it disenfranchises poor and minority voters. He also represented a Roswell man who wanted to raise chickens and roosters in his backyard.
Barnes said that after leaving office he has watched Republican rule at the state Capitol with growing dismay and finally decided in 2009 that instead of complaining about the problem he would try to fix it.
Education has been a cornerstone of his bid. He has pledged to fund more money for schools by scrapping special interest tax exemptions and has also said that improving Georgia's education system would be the strongest way to ensure that jobs return to the state.