How important is Iowa in determining who will become president? Consider this: Since the 1976 establishment of the Iowa caucuses as the real first-in-the-nation presidential contest, just days before New Hampshire's first-in-the-nation primary, nobody has won either the New Hampshire primary or his party's presidential nomination without finishing first, second or third in Iowa. Iowa is, in a word, crucial.

But now Arizona Sen. John McCain's presidential campaign is about to defy history by skipping the Iowa caucuses and seeking to jump-start the Arizonan's campaign in New Hampshire. If precedent is any guide, McCain's withdrawal from Iowa all but guarantees that either publisher Steve Forbes or former Cabinet secretary Elizabeth Dole or Family Research Council President Gary Bauer will become the Gary Hart of the 2000 Republican race.

In 1984 Hart, a Colorado Democratic senator barely registering in the national polls, finished a distant but surprising second in Iowa to the heavy favorite, former vice president Walter Mondale. Only eight days later, what had been just a ripple in Iowa had become a tidal wave in New Hampshire that swept Hart to an upset victory.

The Republican story up to now is straightforward. In every presidential campaign since 1964, the Republicans, one year before the nominating convention, have had a front-runner who led by 10 percent or more in the major surveys. In every single case, the Republican convention, one year later, has given its nomination to that earlier front-running candidate. A year before the 2000 GOP convention, the party has in Texas Gov. George W. Bush the apotheosis of all front-runners.

In the political narrative, Bush is the fearsome, all-powerful dragon. Who will be cast as the underdog Saint George to slay the Texas dragon will be determined in some 2,500 precinct caucuses in church basements, schoolhouses and libraries in Iowa on a frosty Monday evening next February. Auditioning for the Saint George role in the GOP psychodrama probably will be candidates Bauer, Dole and Forbes -- but not John McCain.

In every political campaign, there are, as McCain's advisers emphasize, really only two finite resources -- time and money. Candidates have to decide where best to spend each. But because of the endlessly deep pockets of GOP candidates Forbes and Bush, campaign money is not a finite resource for either man. This complicates the strategy of all the other candidates.

McCain's people point out that his New Hampshire support has grown this year from 3 percent to 16 percent -- placing him second there behind Bush -- after more than a dozen personal visits to the Granite State. What they are reluctant to confront is that in 1987, Tennessee Sen. Al Gore branded the Iowa system "madness" and tried to jump-start his own presidential campaign in New Hampshire, where he finished fifth with 7 percent of the vote.

If a candidate is unable to spend money somewhere, then the candidate has to compensate by spending time. McCain's advisers argue that with his strong opposition to federal funding for ethanol and his lack of a high profile on the party's social and moral issues, he is not a good fit with the Iowa Republicans, where one-third of the caucus-goers are committed to the Christian Right and another one-third are involved directly or indirectly in agribusiness.

Democratic political consultant Tad Devine is an admirer if not a supporter of McCain. Devine knows Iowa and New Hampshire from service in the Mondale, Michael Dukakis and Bob Kerrey presidential campaigns. He thinks McCain is making a fatal mistake. Iowa's campaign and results influence New Hampshire voters (who would never admit it), insists Devine, "especially those who are looking for an alternative to the front-runner." By his absence, McCain is "giving somebody else the coveted opportunity of becoming that alternative."

More important, all the free media -- the TV news and print reporters -- will focus on the Iowa story heading into New Hampshire: the slightly bruised favorite, the rediscovered challenger, the against-the-odds underdog. Overlooked, if not forgotten, by the press would be the candidate admired for his unparalleled personal courage who ducked the first event.

By his decision not to compete in Iowa, McCain, probably the most popular candidate in both parties among the political press corps, could well be sentencing himself to a media blackout in that critical three-week period before the New Hampshire primary and to also-ran status in the 2000 race.