Perdue knew his dad probably wasn't going to make it. So he spent the next three weeks at Houston Medical Center, watching over him. That gave him plenty of time to think about his meteoric ascent to the top of the Senate.
After seven years as a senator, he had risen to majority leader and then president pro-tempore. But the power he wielded didn't let him make the fundamental changes he believed the Legislature, and his Democratic Party, needed.
"It gave me time to reflect on who I was as a person, what I believed and whether I wanted to continue this political charade, " Perdue said. "The emotion of watching your father slip away had a lot to do with answering the question, 'Sonny, are you going to do what's right in your own heart?' "
So before his father died, he gave up his job as the Senate's second in charge to then-Lt. Gov. Pierre Howard and dropped his Democratic stripes to become a Republican.
The Republicans greeted him with open arms, and soon touted him as one of their leaders.
But life as a back-bencher had a serious downside. Stripped of choice committee assignments and forced to watch his legislation die, he became the poster child for what happens when you switch to the minority party.
Four years later, he's given up his Senate seat in hopes of becoming the poster boy for something completely different: a revolution in state government. To his mind, his race for governor is a quest to free Georgia from Democratic tyranny, with Gov. Roy Barnes playing the role of King George III.
"He has spent four years trying to prove to the state of Georgia that he's the most powerful, in-control governor we've ever had, " Perdue said.
Redistricting prompted run
The energy and drive Perdue has put into his campaign are all the more remarkable because, a year ago, he didn't have any plans to run. He hadn't been a Republican long, and if he ran, Democrats were sure to play up his sponsorship of legislation that deregulated natural gas markets. Georgians were still angry over the skyrocketing gas bills that followed.
Then came the Democratic machine's once-a-decade redrawing of legislative and congressional lines. All but guaranteed they would remain the minority party for years to come, Republicans were apoplectic.
They blamed Barnes, and dozens of legislators and other Republican leaders turned to Perdue to champion their cause. Within a few months, he quit his Senate seat to run for governor.
His most vocal critic in the Legislature, Senate Majority Leader Charles Walker (D-Augusta), sees Perdue's candidacy as a bitter bid for personal and political redemption.
"He has a hole in his soul. He can't seem to be fulfilled, " Walker said. "Wherever he goes he finds absolute frustration. He had no substantial political victories to claim.
"He thinks he is the smartest politician in the state. He really believes that. His emotional range goes from 1,000 percent positive to 1,000 percent negative."
Hometown folks who have known Perdue for years don't see that.
"He's a good Christian person. Sonny's the same one day to the next, " said Tina Evans, manager of the White Diamond Grill in Bonaire's tiny downtown, where Perdue is one of the regulars.
Just down the road from Evans' diner are six 49-foot-tall silos and a green, wood-framed, single-story building containing a white board listing crop prices, known as the Bonaire Board of Trade. No flashing neon sign spells it out, but this is Houston Fertilizer and Grain, the home of the Perdue business empire.
With six locations in Georgia and one in West Monroe, La., it sells farmers fertilizer and seed and buys their crops to sell in bulk to big distributors. Since building Houston County's first grain elevator, Perdue has also expanded into the trucking business.
Football and vet school
He didn't start out planning to run a grain business any more than he grew up wanting to be governor.
Perdue played quarterback at Warner Robins High School and was recruited by several colleges. He decided to be a walk-on at the University of Georgia, where he studied to be a veterinarian.
His football career didn't get very far at the big school.
"I had a problem with SEC football. I was small, but I was slow, " he jokes.
In his second year, he gave up football to prepare for vet school.
Still, he managed to stay above the crowd. When he went home to see his parents, he would fly his J5 Piper Cub, landing on Highway 96 in town as he'd seen the local cropdusters do. He still flies his own four-seater plane to campaign events and home, but he uses the local airport in Perry.
Following vet school and a tour in the U.S. Air Force, he worked as a veterinarian in North Carolina before coming back to Georgia to start his agribusiness.
In 1980, Houston County officials asked him to serve on the zoning board. He had no idea it would be the start of a two-decade-long career in politics.
His daddy had been a Roosevelt Democrat, and Democratic candidates had been the only choice for generations of his family. So Perdue was a Democrat. Almost everybody was in Bonaire.
In 1990, he ran for a state Senate seat and won. A bit of an idealist and itching to contribute, he wrote Lt. Gov. Howard a note after his first year in office, asking for more responsibilities. He got them. In virtually no time, he was a committee chairman, then majority leader, and, finally, Senate president pro-tempore.
But Perdue said he never got used to the kind of backroom deals and questionable spending projects that went into passing bills. And he and Walker, one of the Legislature's most skillful wheeler-dealers, mixed like gas and fire.
One year, Walker requested a local assistance grant --- known in the Statehouse as legislative pork --- simply by submitting the designated form with the figure $300,000 written on it and a note saying it was for Augusta projects. Senate Appropriations Chairman George Hooks (D-Americus), didn't know what the money was for, but it passed the chamber anyway.
That was the kind of thing that frustrated Perdue. So after the 1998 session, he switched parties.
"I thought I was becoming part of the problem, not the solution, " he said. "I had enough idealism to think I could change that. But I decided if I could not have the effect of changing government from the inside . . . I felt like I had to do it from the outside."
Targeted for role in gas deregulation
He pledges that if elected governor, he'll thoroughly audit the state's books, exposing the record of corruption and mismanagement he says the Democrats have built up over the years.
But his record has a problem of its own. As one of the Senate's Democratic leaders, he led the way on a bill deregulating natural gas. Over the next few years, bungled implementation and high gas prices soured Georgians on what Perdue had hoped would be one of his major accomplishments.
Although almost every legislator, including Barnes, voted for Perdue's bill, it was Perdue who received much of the blame when things went wrong. He cringed at gas companies cutting off service to thousands of Georgians because they couldn't pay their bills.
He said the state had a "moral obligation" to provide help. He also called for legislation to undo some of the damage. A bill passed in this year's session, but it was a version pushed by Barnes, adding insult to injury.
Perdue's first year as a Republican coincided with Barnes' first year as governor.
"When he was elected, I thought of him as someone we could work with, " Perdue said.
But by Barnes' second year, he had changed his mind, citing the Democrats' refusal to consider voting for any Republican amendments to the governor's school reform legislation and Barnes' general dominance over state government. That was also the year Republicans started referring to Barnes as "King Roy, " a moniker they've repeated on the campaign trail.
That name led to the most attention-grabbing moment of Perdue's campaign so far, the debut of a video in which Barnes was portrayed as giant, power-mad, crown-wearing rat. The film wasn't used in a TV commercial, but it was available on Perdue's campaign Web site.
Some have criticized it as a cheap shot, but Perdue said he made the film because the campaign needed attention and couldn't afford to pay for it. While he's raised more money than his two Republican opponents, his campaign had less than $900,000 in the bank as of June 30, compared with Barnes' more than $9 million.
Perdue also has worked to shake the impression that he was hand-picked by state GOP Chairman Ralph Reed and Republican leaders, a charge leveled by his primary opponents. Many assume that because of such support, Perdue is the front-runner in the race for the nomination, although an Atlanta Journal-Constitution/WSB-TV poll taken last week shows him in a dead heat with Linda Schrenko and Bill Byrne.
Perdue said the last thing he wants is to be known as a status-quo Republican owned by party fat cats.
"I am not anybody's candidate. This [the primary] is not an anointing, " he said. "We've been working harder than anybody else to earn the nomination.
"I am a workhorse who believes in fiscal responsibility. I am not looking for a blue ribbon. This is not an ego trip for me. I feel very passionately that things need to change."
Georgia has not elected a Republican governor in 130 years. Can one of these three change that?