WASHINGTON — Godot isn't likely to show up for the Republicans. Like the characters in Samuel Beckett's play, the Republican establishment probably will wait in vain for a white knight -- Jeb Bush, Chris Christie and Paul Ryan are the most oft-cited -- to rescue the party's presidential prospects.

The Republican field seems set, with the major contenders likely to be former governors Mitt Romney of Massachusetts, Tim Pawlenty of Minnesota and Jon Huntsman of Utah, and possibly Rep. Michele Bachmann of Minnesota. This assumes that Bachmann and Huntsman will enter the race; the party's 2008 vice-presidential candidate, Sarah Palin, former New York Mayor Rudy Giuliani, as well as Texas Gov. Rick Perry, may, too.

On the surface, it isn't an especially formidable lineup, though circumstances, campaigns and upset victories can change that.

The considerations, smarter political strategists and history tell us, will be match ups: How the strengths, weaknesses, similarities and differences contrast in the early contests in Iowa and New Hampshire, which are likely to be where a winner emerges.

Differentiating issues, as always, will come into focus as the campaign evolves and the initial debates occur. By traditional measurements, the ideological divides are minimal. All the contenders are conservatives, favoring spending and tax cuts, less regulation. They also are, to varying degrees, social conservatives who oppose abortion, gun control and gay marriage.

Still, there are telling nuances. The former governors, Romney and Huntsman and, to an extent, Pawlenty, are more mainstream, business-friendly, establishment conservatives. Bachmann and Palin, if she joins the race, are populist right- wingers playing to the cultural, religious and social-issues base of the party.

Two other populist wannabes seem less serious these days. Former House Speaker Newt Gingrich's campaign has virtually self-destructed before launching, and ex-Pennsylvania senator Rick Santorum's major achievement so far has been to assail national icons: criticizing President John F. Kennedy for being insufficiently Catholic, and last week chiding Republican Sen. John McCain of Arizona, a prisoner of war for six-and-a- half years during the Vietnam War, for not understanding enhanced interrogation.

The Libertarian Congressman Ron Paul of Texas is sui generis; he'll command 5 percent to 10 percent or more of the vote in most contests.

Romney and Huntsman, as rivals, are straight out of central casting: both are Mormon, smart, attractive, wealthy former governors, ex-businessmen. Romney has better corporate credentials and Huntsman has more foreign-policy experience, with two stints as an ambassador.

Both have potentially lethal liabilities: Romney promulgated a Massachusetts health-care law that many Republicans believe was a precursor to the plan enacted by President Barack Obama; Huntsman served as Obama's envoy to China, a double liability in the eyes of many conservative Republicans.

The conventional wisdom of the Washington punditocracy in recent weeks has been that Pawlenty is the one major contender who can straddle both camps, acceptable to the more mainstream economic conservatives and to the movement's social right, while a favorite of neither. True, though the problem for "tweeners," as such middle of the road types are sometimes called in politics and sports, is that they don't arouse much passion, often the essential ingredient for success in primaries.

There are crucial early decisions that will shape the outcome. It's a good bet the ultimate nominee will win either the Iowa caucuses or the New Hampshire primary. That has been the case with 17 of the past 18 major party nominees, the exception being Bill Clinton in 1992, when there wasn't a contest in the Iowa caucuses.

Iowa, where social conservatives and the religious right have a disproportionate influence, is a must-win for Bachmann, or for Palin, for that matter. It's hard to see a path to the nomination for Pawlenty if he can't win in his neighboring state.

Other candidates such as Huntsman probably will skip Iowa. The toughest decision will be for Romney, the frontrunner, who finished second in the Hawkeye State in 2008. If he makes only a token effort and Pawlenty wins, it could jeopardize his front- running status, as could a major effort that's unsuccessful. As of late last week, the Romney campaign was still undecided on Iowa.

Despondent Republicans might look back to similarly depressed Democrats 20 years ago; all the heavyweights -- Mario Cuomo, Ted Kennedy, Al Gore -- were sitting out a race against an incumbent president, leaving the field to a group of second- raters.

Out of the pack emerged a nominee, the governor of Arkansas, who proved to be a pretty fair politician.

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