There is a great temptation to dismiss a lot of what is happening in presidential politics in this season as ephemeral nonsense. The candidates seem silly, their maneuvering cynical, their disputes trivial, their activities peripheral. Right on all accounts, but wrong in a larger sense.

The prologue to an American presidential election is not peripheral to its outcome. Jimmy Carter won the presidential race of 1976 by the way he campaigned for the Democratic nomination in 1975 — setting a pattern that has largely governed American politics ever since. In fact, in nine of the 10 contested nomination fights since 1980, the candidate leading in the last poll before the Iowa caucuses won his party’s nomination. (The lone exception doesn’t count. It occurred in 1988, when former Sen. Gary W. Hart of Colorado led the polls. His campaign was fatally injured by a sex scandal.)

But there’s more than that to contemplate as we enter the last month of the year before. In nine of the 10 contested races since 1980, the candidate who raised the most money before the actual election year went on to win the nomination, according to figures assembled by William G. Mayer, a Northeastern University political scientist. (The lone exception here doesn’t count much either. It was former Treasury Secretary John Connally, who raised $12 million for the 1980 election — a huge amount in those days — and won just one Republican delegate in a gold-plated but ill-fated campaign.)

None of this data means that if one candidate were to lead the polls this year and lead the pack in fund-raising, he or she is guaranteed to win the Democratic nomination. (One candidate does lead both categories in this contest. He is former Gov. Howard Dean of Vermont.) This data reflects only what has happened rather than predicts what will happen. But it is a powerful indicator of how nomination fights have come to be conducted — and resolved.

The compelling thing about these figures and these tendencies is that in most of these cases, the candidate out front in the poll soundings and in the fund-raising derby didn’t strike fear among his rivals and party leaders that his nomination would bring the party an electoral disaster in November. Ronald Reagan had many skeptics in 1980, but his two terms in California and his strong showing in the 1976 nomination fight with President Gerald R. Ford lent credibility to his campaign. The man who lost most decisively in the past quarter-century, former Vice President Walter F. Mondale, was nonetheless considered by his fellow candidates and by party leaders to be a legitimate contender against Reagan in 1984.

This time, Dean is the front-runner, but he’s also giving leading Democrats the jitters. That could mean, and it sometimes does, that establishment Democrats are out of sync with public sentiment, a notion that is buttressed by Dean’s success in recent months in mining an entirely different vein of financial and popular support than that of any previous Democratic contender. But it could also mean that party leaders, who are governed less by polls than by their own perceptions, are onto something.

Every presidential election has its own character, but few have been conducted in an atmosphere of alienation like the one that prevails right now. The country has been divided evenly for years — the popular vote in the last presidential election, for example, can be regarded as a statistical tie — and those divisions are reflected in the Congress, where the Republicans’ controlling margins are razor-thin. The latest Time/CNN Poll shows example after example of unified Democratic opposition to President Bush matched against unified Republican support for the president.

Some 76 percent of Republicans, for instance, believe that the president is doing a good job handling the economy, but 68 percent of Democrats say he’s doing a poor job in economic affairs. Forty-seven percent of Republicans say they are likely to vote for the president’s re-election, while 48 percent of Democrats say they are likely to vote against giving him a second term.

The important question that these poll results raise: Are the Democrats crazy to nominate someone as polarizing as Dean, or, in an era of alienation, when the Republicans will renominate a polarizing president, is he just the thing?

The element in this election that makes that question especially complicated is the breathtaking swiftness of Dean’s rise. An Ipsos-Reid Poll conducted last month put Dean at the top of the Democratic heap, but the same poll taken in April gave him less than half the support recorded by Sens. John F. Kerry of Massachusetts and Joseph I. Lieberman of Connecticut, and Rep. Richard A. Gephardt of Missouri. If Dean were a pitcher rather than a politician, you’d use the word “phenom” to describe him. (Illuminating quote attributed to the pitcher Dizzy Dean: “I ain’t pitchin’ no curves today, fellers. Nuthin’ but fastballs.”)

All of which explains the unusual importance this time around of the angling and activity that precede the caucuses in Iowa and the primary in New Hampshire. Dean is planning to spend $400,000 in a 10-day period in Iowa, an astonishing burst of advertising in a period of time when presidential campaigns ordinarily go dark. But he’s not the only one. Kerry has had ads on the air for weeks now.

There was a time when presidential candidates tried to play down expectations and broke into hives if news accounts called them the front-runner. Now they all want to be one — before it’s too late.

David Shribman is a columnist for Universal Press Syndicate.