Unlike horses and dogs, presidential candidates offer no easy way for the betting man to turn a buck. It’s not that one can’t find a bookie to take the wager — the Internet long ago solved that problem. It’s just that candidates are, as a group, more poorly trained, more easily spooked and more prone to catastrophic stumbles than any 50-to-1 filly running at Pimlico on a muddy track.

With horses and dogs, the gambler can at least have faith that the turf accountants are in the ballpark when they set the odds. Racing animals tend to perform in patterns, echoing past achievements and reflecting their fine breeding. Presidential candidates, on the other hand, are far more likely to implode suddenly and for no good reason, like a drummer from Spinal Tap or a senator from Virginia.

Just one year ago, the Old Dominion’s George Allen was crowned the Republican front-runner of the 2008 presidential cycle by the prestigious National Journal, one of several costly pharmacies that political junkies use to feed their addiction. Today, there is not a handicapper in the business who would place Allen within 10 miles of the White House. And the man who said “macaca” is not the only one to have fallen.

Former Virginia Gov. Mark Warner, once a leading Democratic contender, has bowed out altogether in the name of family. Sen. Russ Feingold, the great liberal hope from Wisconsin, decided this month to focus on his senatorial duties now that Democrats control Congress. The good doctor from Tennessee, Sen. Bill Frist, left the race on Wednesday, a victim of an insider trading investigation and his own dubious diagnosis of the bed-ridden Terri Schiavo. And Massachusetts Sen. John Kerry, who fell just one state short of the presidency in 2004, has come up lame from the self-inflicted wound of a badly bungled joke last month.

But none of this tumult has prevented the handicapping class from simply posting the new odds on the giant chalkboards they keep in their newsletters and magazines. To facilitate this process, as part of the ninth annual American Democracy Conference, University of Virginia political scientist Larry Sabato and editors from the National Journal gathered together campaign advisors for 10 presumptive presidential campaigns for a five-hour conference on the 2008 election. Hundreds of overdressed political consultants, activists and journalists gathered Thursday in the wood-trimmed auditorium of the Ronald Reagan Building to watch the railbirds do their work. Because it was a federal building, cigar smoking was not allowed.

First Chuck Todd, the esteemed tout in chief of the National Journal’s Hotline news service, prodded a panel of Republican presidential advisors to name the new front-runner for the GOP nomination. An advisor to Arizona Sen. John McCain said that it was former New York Mayor Rudolph Giuliani. An advisor to Frist said the front-runners were McCain, Giuliani and Massachusetts Gov. Mitt Romney. An advisor to Romney said it was either McCain or Romney. “I don’t think it really matters,” he wisely added.

“To quote Secretary Rumsfeld, there are so many unknown unknowables right now,” said Alex Vogel, the Frist strategist, who did not know as recently as last week that his candidate would drop out of the race.

Soon the conversation turned to how much money candidates in the coming cycle would need to raise. Vogel said he believed that top-tier candidates would need to bank at least $30 million by next spring, and that New York Sen. Hillary Clinton, if she wins the Democratic nomination, could raise as much as $500 million, about 50 percent more than Kerry raised in 2004. This prompted David Kensinger, an advisor to Kansas Sen. Sam Brownback, to offer a metaphor so Delphic in its complexity that it seemed to mean something profound.

“A campaign is analogous to a power plant,” he said. “A power plant takes coal, it spins turbines, and then creates power, which is what they sell. A political campaign is in the business of making votes, so it can gain political power. Money is like coal, and communications, the things you buy with the money, are your turbine. If you are in a situation where there is more coal than there has ever been before, then the relative scarcity of coal is less; therefore the value of coal is less. If it takes more coal to move the turbine than ever before, then coal is less efficient and it becomes less valuable again, and if the substitute mechanisms available — natural gas or whatever — are lower than ever before, then coal is less valued.”

He was just getting warmed up. “If you were making an econometric function of how valuable is money, and you looked at relative scarcity, efficiency and the cost of substitute goods, I’ll make you the case that money, per se, especially early money — the bar is higher than ever before and the money is of less marginal utility than ever before.”

It was unclear what the natural gas was supposed to represent. “I thought I had a stroke there for a minute,” said panelist Rich Galen, an advisor to former House Speaker Newt Gingrich, who was sitting next to Kensinger.

A few minutes later, the Republican panel was replaced by Democratic advisors who represented five presidential candidates. No one came to speak for Clinton or Illinois Sen. Barack Obama, two of the presumptive front-runners, nor for Tom Vilsack, the former governor of Iowa who recently announced his candidacy. But that did not prevent the panelists from making bold predictions.

“I think people at their peril underestimate Tom Vilsack,” observed Doug Sosnik, an advisor to Connecticut Sen. Chris Dodd’s presidential effort. Steve Murphy, a veteran consultant for New Mexico Gov. Bill Richardson, said healthcare would be the top domestic issue in 2008. “In my opinion, the Republicans have demagogued us on the national security issue as much as they can, and that dog is on the soft food now,” he said. Anita Dunn, a consultant for Indiana Sen. Evan Bayh, warned the panel not to underestimate her candidate. “If you don’t win the Midwest heartland, the margins don’t matter,” she said, noting that Bayh had twice been elected governor of his home state.

In total, the consultants prognosticated for two hours, but none of the talking shed much light on who will be the next two nominees for the presidency of the United States. In the current National Journal rankings, McCain and Romney are listed as the Republican favorites. For the Democrats, Clinton is listed with former North Carolina Sen. John Edwards. But the only certainty is that the rankings will change, that the unexpected will happen.

Back in 1990, two years before Bill Clinton won the White House, the leading Democratic contender was Mario Cuomo, the governor of New York. In 2002, none of the touts and tipsters could have foreseen Vermont Gov. Howard Dean’s surge along the outside rail into front-runner status. Few expected Sen. John McCain to mount a serious challenge against George W. Bush two years before the 2000 election.

At the start of the conference, long before the panelists took their places onstage, James Carville, the former Clinton advisor, reminded everyone how little they really knew. “In the long grueling, tired, freezing-cold, irritating fog of a campaign,” he said, “we just know many delicious things will happen.” One could see a mischievous glint in Carville’s eye, the same glint one sees in the eyes of a trackside gambler before the gates spring open. Not knowing the outcome, Carville was reminding the crowd, is what makes it so much fun.

Rarely does an incumbent U.S. senator panic over the possibility that a new and little-known advocacy organization might broadcast a political attack in his home state. Yet the mere prospect of confrontation with VoteVets.org — a political action committee organized by military veterans of Iraq and Afghanistan — seems to have frightened Sen. Jon Kyl, R-Ariz., into launching his own preemptive attack on the group.

The mainstream media sometimes tells us more than we want to know about some U.S. senators. Earlier this week, the New York Times informed us that Hillary Clinton has spent time with her husband on 51 of her last 73 weekends but on only one day in February 2005. And just this morning, the Washington Post walks us through Bill Frist’s early-morning bathroom routine — shower, hair dryer, the whole bit — by way of telling us that he sometimes performs heart surgery on gorillas at the National Zoo.