Dec. 24 (Bloomberg) -- The gates are about to open for the U.S. presidential race. The early odds, if history is an indicator, will be close to the mark.

Looking at bookmakers in Las Vegas and London, and the crystal balls of a few seasoned political practitioners from both parties, a clear line has emerged.

First are the elements of a Democratic year. Pay less attention to the close general-election trial heats; they are lagging indicators as Ronald Reagan, circa December 1979, and Bill Clinton, circa December 1991, could have told you.

The fundamentals -- the country's mood, the political cycle, the likely shape of the economy, and the movement of certain constituencies such as Hispanics and young voters -- all tilt Democratic.

Thus, lay down 7-to-win-5 on a Democrat taking the presidential oath of office 13 months from now, 2-to-1 that it's a Republican, and 20-to-1 an independent or third-party candidate.

The odds for the Democrats to win the presidency include:

HILLARY CLINTON: If the senator from New York wins the Jan. 3 Iowa caucuses, she's a prohibitive favorite for the nomination. She's the only candidate who could survive a couple of early losses and conceivably bounce back. Clinton, 60, would have a difficult general-election matchup with Senator John McCain of Arizona; against anyone else, she'd be a favorite.

As of today, however, she's an underdog in Iowa and her aura of inevitability is gone. Still, given all the vicissitudes, if you could only bet on one candidate, there is no stronger choice. The odds of Hillary Clinton being the 44th president: 3-to-1.

Obama Tested

BARACK OBAMA: If this horse breaks into the open, he may be the political equivalent of Secretariat. Yet, as well as the freshman senator from Illinois has done, he'll face withering tests in the next few weeks -- Clinton supporters are already going after him personally -- and nagging doubts about whether race and inexperience make him vulnerable in the run-up to the election.

Nevertheless, victories in Iowa, and in New Hampshire on Jan. 8, are within sight for Obama, 46, and would shake up the political universe. His chances of becoming the first African- American president: 7-to-2.

Edwards Organized

JOHN EDWARDS: An Iowa win remains within reach. ``Obama has a lot going, but we think we have the best organization and the most-committed caucus-goers,'' says David Bonior, Edwards' campaign manager. Edwards, 54, the 2004 Democratic vice presidential candidate, does better than anyone in either party in many general-election head-to-head polls. Yet it's difficult to see how he can marshal the financial resources and political support for a war of attrition in the primaries. Odds for the North Carolinian: 10-to-1.

Of Senators Chris Dodd and Joe Biden and Governor Bill Richardson, never will so many political heavyweights have dropped out so quickly; the rest of the field combined has odds of 40-to-1.

The Republican calculations are dicier:

MITT ROMNEY: His Dec. 6 speech about religion didn't put the issue of his Mormonism to rest, but it did provide a much- needed shot in the arm for Romney, 60, especially when it was followed by the endorsement of the influential conservative magazine, National Review. The campaign is right to ignore poor standings in national polls; wins in Iowa and New Hampshire are the sine qua non of the Romney rationale.

The former Massachusetts governor's general-election prospects have been weakened by a plethora of politically opportunistic policy reversals, ranging from social issues, such as abortion, to immigration and taxes. Still, some Republican has to win the nomination, and no one has a better shot than his 5-to-1 odds.

McCain, Giuliani

JOHN McCAIN: He can come back from the politically dead -- if he wins the New Hampshire primary. He is the Republican that Democrats fear most in the election.

However, McCain, 71, is still irrationally reviled in some Republican circles. If he gains traction, the immigration- bashers will come after him with a vengeance. He's a great boxing fan and probably can cite fighters who have won despite the 8-to-1 odds he faces.

RUDY GIULIANI: The toughness and resilience of the former New York mayor is one of the great stories of 2007. To the shock of most Republican insiders, Giuliani, 63, has led in the national polls throughout this year.

The Rudy scenario of jump-starting a campaign after the first few contests has never worked before, and his personal problems/scandals are taking a toll. With a third-party bid looming by religious conservatives if he's the nominee, mark him down for 10-to-1.

Huckabee, Thompson

MIKE HUCKABEE: The flavor of the month is galvanizing the religious right. He is the most natural campaigner in the Republican field. An Iowa victory is essential and possible. Where Huckabee, 52, goes then, other than a few select Southern primaries, is problematic, particularly a path to the nomination at the Republican convention in Minnesota at the end of the summer. A 12-to-1 shot.

FRED THOMPSON: In September he was smart, charming and acceptably conservative. The only debate in most party circles today is whether the prospects for Thompson, 65, were overrated or he has blown it. In any case the Fizzle of 2007 is, charitably, at 20-to-1.

The odds on any other Republican are 25-to-1, as widespread dissatisfaction persists about the choices. If former Florida Governor Jeb Bush had a different last name, these odds would be a lot shorter.

An overarching consideration, Democratic wiseman James A. Johnson notes, is which party's nomination will be decided earliest. He is convinced it will be the Democrats.

In eight of the past 10 elections, the party that settled its nomination first won the presidency in November.

(Albert R. Hunt is the executive editor for Washington at Bloomberg News.)

To contact the writer of this column: Albert R. Hunt in Washington at ahunt1@bloomberg.net.

Last Updated: December 23, 2007 10:18 EST