When Iowa comes to vote tomorrow, the caucus-goers’ main concern will be to find a candidate who best represents their point of view. At the back of their minds may be whether the person they support can be elected in November. but compatibility, rather than electability, remains the prime motivator.

There is another question that might be asked to determine who would be the best general election candidate. Who would the rival party pick as the easiest to defeat?

The sudden death states of Iowa and New Hampshire will winnow out the field. So it is farewell to Mike Gravel, whose intemperate outbursts helped brighten up the debates. Goodbye, too, to Dennis Kucinich. We shall miss him peering over the lectern like Snow White’s Happy dwarf. Nor can veteran campaigners Joe Biden or Bill Richardson expect to survive. On the Republican side, Duncan Hunter will surely follow Tom Tancredo as a 2008 election footnote.

Which leaves eight possible presidents on the starting line. The three Democrats offer a trio of aunt sallies for Republican strategists. John Edwards is, perhaps, both the most difficult and the easiest to defeat. As a white male southerner, his profile fits that of a winner. He has an attractive, charismatic wife, and a young family, tinged by tragedy. He is good looking and serious. As John Kerry’s sidekick in 2004, he gained useful experience and learned many hard lessons. His $400 haircut was worth every cent for alerting him to how small events can hijack a campaign.

He is a populist fighting as a Washington insider turned outsider. As a trial lawyer, he could be painted by Republican opponents as an ambulance chaser, though his message is targeted at Americans who are concerned with the victims of corporate indifference rather than defending businesses from fraudulent claims. His contradictory platform of reducing Washington’s influence by giving the federal government more powers owes more to European democratic socialism than to the American way, but he may prove hard to beat. In polls, Mr. Edwards easily outstrips all Republican candidates except for Rudy Giuliani and John McCain, both of whom he still beats most of the time.

Barack Obama is inexperienced but charismatic, a candidate for change or, as President Clinton likes to paint it, a rash throw of the dice. As an African-American, he could, perhaps, mobilize a section of the population famous for not turning out to vote. As Mrs. Clinton’s surrogates have discovered, he is an easy target for smears and dirty tricks. If America is really ready to elect an African-American, and there are few signs we are witnessing such an historic abandonment of prejudice, there are few more attractive candidates than Mr. Obama. If we are not on the threshold of such an historic breakthrough, he is the candidate most vulnerable to an onslaught by “apolitical” groups like the Swift Boat Veterans.

What do Republican strategists really think of having to counter the Clintons? Both President bush and Karl Rove concede that Hillary Clinton would be a formidable opponent, yet they also point to the bedrock of distrust and disdain that has lingered around the couple since they last inhabited the White House. To win, Mrs. Clinton must become likeable and shake off many of the preconceptions we have about her, which will not be easy. Yet her organization is so formidable, her determination so evident, her discipline so fierce, her campaign so well funded, that she would be no pushover. And she has Bill Clinton, a bunker buster of a campaigner. Republicans say they relish a grudge match with the Clintons, but how many of them genuinely expect to win it?

The GOP also has a trio of aunt sallies. As the limelight has moved to Mike Huckabee, he looks increasingly ill disciplined and vulnerable. His southern evangelical zeal may energize the Religious Right, but it scares the daylights out the rest of us. The Democrats will relish the chance to probe his views on predestination and Charles Darwin, while conservatives find it hard to stomach his affection for big government and his indifference to raising taxes.

As the assassination of Benazir Bhutto showed, Pastor Huckabee is way out of his depth on foreign policy and national security. His withdrawal of negative ads while providing them to the press shows a cynicism and amateurism which presages many a false step in a general election. He shed 110 pounds and many inconvenient memories of his policies as governor of Arkansas before entering the race. How soon before the fat man inside him reemerges?

Mitt Romney provides a similar butt for Democratic attacks. Mr. Kerry floundered as he tried to explain a single flip flop on the Iraq War. How can Mr. Romney defend himself against reneging on all the policies he embraced in order to become governor of liberal Massachusetts? The Democrats need not raise the issue of Mormonism in the sure knowledge that it remains of preeminent importance to large numbers of southern Christians. Mr. Romney, too, failed the Bhutto test. Confusing Iran for Iraq may be a common error, but it is not excusable in a man auditioning to become commander in chief.

Those who need to be reminded why Rudy Giuliani would instantly become mired in interminable awkward questions about his private life, his business life, his family life, his time as mayor, his time before 9/11, his time after 9/11, his management style, and his temperament, would do well to read Elizabeth Kolbert’s catalogue of aberrations in the current New Yorker. A month ago the Giuliani campaign stalled as he was obliged to explain just two scandals: his devotion to Bernard Kerick and who paid for his mistress’s security detail. Other skeletons tumbling out of his closet will keep him offering excuses right up to election day. His glib formulation, “Nobody’s perfect,” is hardly a winning campaign slogan.

Which brings us to two grumpy old men. It is generally thought that Fred Thompson has lost the GOP candidacy through his somnambulant approach to the race, and that may well turn out to be the case. It is best to run for the presidency, not amble towards it. but from the Democratic point of view, Mr. Thompson is a formidable opponent. His high public profile gives him enormous name recognition and personal appeal; his low profile so far in the race means he still has an interesting story to tell. And he has a mountain of cash with which to counter the expected losses in Iowa and New Hampshire.

John McCain, too, is a hard nut for the Democrats to crack. He has been running for the presidency for so long that, like Mrs. Clinton, there are few surprises left to expose. His maverick personality and failure to pander over everything from immigration and campaign finance to ethanol and the surge make him difficult to paint as an extremist, yet he remains a solid conservative.

Independent voters like him, as do conservative Democrats who are not happy with their party’s shortlist of candidates. What is more, he is the only Republican candidate, including Mr. Giuliani, whom polls persistently say can trounce Mrs. Clinton. Which is what this election may turn out to be all about.

nwapshott@nysun.com