Florid, balding and flamboyant, Jennings, an attorney by training, sees beauty in the nuts and bolts of a job that is full of technical detail: chairman of the Arizona Corporation Commission.
"To me, what we do is fascinating because it draws on so many things," he says. "You just can't do this unless you sit down and look at something in all of its intricacy. And sometimes the amount of detail is staggering, but that's the nature of utilities."
He also relishes his role as Democratic agent provocateur. Last month, when Governor J. Fife Symington III and Republican state Representative Jeff Groscost fired off nearly identical letters urging him to slow the pace of electric deregulation, Jennings would have none of it.
In their letters, Symington and Groscost argued that, in the wake of the massive blackouts that hit the West this summer, Jennings and the commission should move with caution toward deregulation.
"As the power outage demonstrates, safe and reliable power for Arizona citizens depends as much on its neighboring states as it does on Arizona's electric utilities," Symington's September 18 letter stated. "We simply must have regional standards that are mandatory for electric utilities operating in the Western area before we move into a competitive forum."
Calling Symington a politically "sick animal," Jennings accused the governor and the Republican-dominated Legislature of caving in to pressure from utilities who fear losing out in a deregulated marketplace.
"Sections of the two letters have exactly the same wording, and the tone of both letters reflects the position of those with a vested interest in obstructing the introduction of competition," Jennings wrote the next week.
Jennings pauses midbite as a tall, gaunt man in a bola tie ambles past.
"Hey, it's Rusty Bowers, the environmentalist!" Jennings chides loudly enough to turn a few heads. Bowers, the conservative Republican chairman of the House Environment Committee, nods and smiles wanly as he makes his way toward the door.
"He gets all worked up if you call him that," Jennings explains in a conspiratorial voice. "As if that was some kind of insult or something."
But Jennings has other matters on his mind this afternoon, specifically the upcoming race to decide who will fill the seat being vacated by his fellow Democratic commissioner, Marcia Weeks, who has decided to step down. He uses the occasion to stump for Barbara Sherman, the former Tempe councilwoman who will face off against Republican Jim Irvin.
"She's terrific, perfect for the job," Jennings gushes. "She's got a good record as an advocate, and she knows the issues."
"He's not what this state needs," he says, shaking his head.
"Do Arizonans really want a commission that is controlled by a couple of millionaires?" he asks, referring to the fact that both Irvin and Republican Commissioner Karl Kunasek have hefty personal fortunes to their names. "I don't think so."
Jennings, no pauper himself, produces a manila folder containing a sheaf of charts showing how Arizona's utility customers have historically fared badly under Republican-dominated commissions.
"This is what people can look forward to," Jennings says, brandishing a graph.
But if he is concerned about policy, Jennings also has political interests. He stands to become a wallflower on the three-member commission--whose agenda he and Weeks have largely shaped since 1985--if Sherman, his 11th-hour, hand-picked candidate, does not mount something that resembles a challenge to Irvin's well-funded, smoothly running campaign.
Think of Arizona's three-member Corporation Commission as the Rodney Dangerfield of state politics.
Its members don't have the satisfaction of seeing their names in the paper all that often, and their jobs don't make them instant hits at parties.
Not that what the commission does--regulating the state's utilities and deciding how much they can charge customers--isn't important; it's just that much of it is so arcane that people find it about as enjoyable as a root canal.
There have been times, however, when the commission has become the center of controversy. The last was in 1985, when voters swept Weeks and Jennings into office amid allegations that the two Republican commissioners they replaced were in bed with the utilities.
The uprising stemmed from a series of massive rate hikes the two Republicans had approved, much of which was used to fund construction of the Palo Verde nuclear plant.
This year's race, however, has stirred little interest.
Asked why he hasn't done a survey on the race, veteran political pollster Earl de Berge says: "Frankly, people don't really care about it."