Since the advent of the contemporary primary/caucus-based nominating system, Iowa and New Hampshire have held the keys to victory. 2008 will be no different, though Nevada (for the Democrats) and South Carolina may also play starring roles.

Since 1976, when proliferating primaries and caucuses became the basis for selecting convention delegates, every nominee but one, in both parties, won either Iowa or New Hampshire. The singular exception occurred in 1992 when Iowa’s favorite son, Tom Harkin, rendered the Democratic caucuses moot while Paul Tsongas’s victory in his neighboring state of New Hampshire, along with Bill Clinton’s comeback second-place finish, left the contest unresolved.

The impact of these early contests is dramatic and, like most things in modern life, the magnitude of the effect is accelerating. In 1976, Jimmy Carter garnered 4 percent of the Democratic primary vote in national polls before his Iowa and New Hampshire victories. Within three days of his Granite State victory, he jumped 12 points to 16 percent in the national polls. In 1980 George Bush defeated Ronald Reagan by 2 points in Iowa and saw his national poll standing more than double from 14 percent to 32 percent. (Of course, Reagan went on to win a massive New Hampshire victory and secure the nomination.)

The effect for John Kerry was even more substantial, and the frequent polling allows for some inferences about the separate impact of each early contest. National polling by Quinnipiac had Kerry with a mere 8 percent before the Iowa caucuses, which ballooned to 30 percent just after his win in the Hawkeye State and jumped again to 42 percent after his New Hampshire victory. Newsweek’s polling revealed a similar trajectory, from 11 percent to 30 percent to 45 percent.  

On average, Kerry picked up about 20 points nationally from his Iowa win, and another 13 from New Hampshire.

They don’t call it big mo’ for nothing.

At the root of the big mo’ are two V’s: visibility and viability. Historically, Iowa and New Hampshire account for about half the press coverage of the entire primary season, with the winners absorbing the lion’s share. Moreover, the winner’s coverage is almost all positive. That intense burst of positive publicity is sufficient to fuel the rise of any candidate, while those who fail to partake of the victor’s spoils can never catch up. After winning the two early contests in 1976, Jimmy Carter’s smiling visage graced the cover of both Time and Newsweek. A week after New Hampshire, Henry Jackson won the Massachusetts primary with about seven times as many votes, but never made it to a magazine cover.

Voter assessments of candidates’ viability matter as well. Some will interpret this as a bandwagon effect. It is not, really. In a much earlier column I was pleased to coin Mellman’s First Law of Aphorisms, which states that for every aphorism there is an equal and opposite aphorism. “Everybody wants to be with a winner.” “Everybody loves an underdog.” Well, which is it? Probably neither. But most people (though not all) do want to support a candidate whom they believe has some chance of winning. Early victories provide incontrovertible evidence that a candidate can win. Losses at least raise questions about viability — questions the press reinforces by asking losers daily how long they plan to remain in the race.

This year, Nevada (for the Democrats) and, to a lesser extent, South Carolina will join Iowa and New Hampshire in deciding the parties’ nominees. So while candidates scour the country for funds and sort out the implications of the looming national primary, they need to remember: If you don’t win early, you won’t be the nominee.

Mark Mellman is president of The Mellman Group and has worked for Democratic candidates and causes since 1982. Current clients include the majority leaders of both the House and Senate.