Hanover, N.H. ? Mornings this time of year here are eerily eloquent. They start out crisp, sometimes with a frosty bite that rides the wind from the north and the notches. But within hours the sun’s warmth overtakes the cold, and the black ice — so treacherous at dawn, so threatening to ankles and wrists — is rendered harmless. It is slush by noon.

This is New Hampshire in transition. Long ago, one of the state’s great political scientists spoke of “the thawing wind” and “the springing of the year.” But here in New Hampshire, Robert Frost’s adopted home, what is coming is more than spring. What is coming, too, is the political season.

The sap runs in both, of course, and this year will be no different. Even so, this will be a particularly perplexing season here. The economy is sputtering, war is looming, voters are worrying. In the White House sits a president who lost New Hampshire by 19 percentage points in the 2000 primary and who won the state’s four electoral votes by only a single point in the general election. And while four years ago there were only two men in the Democratic presidential race — of the same generation, of the same general outlook — this spring there are already nine candidates. Two are black. One is Jewish. A third isn’t quite 50.

It sure is crowded up here in the empty spaces of New Hampshire. The state’s primary always attracts oddballs and zealots. (It sometimes prompts bizarre behavior, too; a half-century ago, a scowling Sen. Robert A. Taft of Ohio, a man not given to frivolity, was photographed by Alfred Eisenstaedt holding a red rooster, and a peculiarly handsome one at that.) But the remarkable thing about this year’s race is how many conventional, legitimate candidates there are.

So suddenly the political factors to contemplate include not only George W. Bush’s popularity, the situation in Iraq, homeland security, the price of home heating oil, the unemployment rate and the slide of the Dow. The size of the presidential field is the latest, perhaps even the most important, unknown.

It may mean that, as Charles E. Brereton, who has written four books on the New Hampshire Primary, said the other afternoon, “Anyone can win.” In 2000, Vice President Al Gore needed 52 percent of the vote to take the primary. The winner in 2004 may need not much more than half that. The model may be the 1980 New Hampshire GOP Senate primary, which had 10 contestants (including a one-time state legislator named John H. Sununu, later the governor and White House chief of staff); Warren B. Rudman, a former attorney general, needed only 20.3 percent of the vote for to emerge victorious.

Almost everyone here concedes that Sen. John F. Kerry of nearby Massachusetts has the edge; three Bay State politicians, John F. Kennedy (1960), Michael S. Dukakis (1988) and Paul E. Tsongas (1992), have won the primary in the past half-century. Former Gov. Howard Dean of Vermont, which shares a border with New Hampshire, has a natural appeal in these parts; he is the candidate who most closely resembles television’s President Josiah Bartlet, who, according to the scriptwriters, had the happy fortune to spring right from the rocky soil of New Hampshire. Dean will be surprisingly competitive here.

But Kerry and Dean will not be alone. Rep. Richard A. Gephardt of Missouri drew 20.3 percent in this state in 1988. A more accomplished politician today, he could repeat the trick in 2004. Sen. Joseph I. Lieberman of Connecticut, who ran with Gore in 2000, already has invested considerable time and money here. He can’t be written off. Sen. John Edwards of North Carolina is the young newcomer. A born sweet-talker, he’ll remind voters here of Gov. Jimmy Carter of Georgia, who squeaked out a close victory over Rep. Morris K. Udall of Arizona in 1976.

The size of the field may present the Democrats with difficulty, but it also stands as a symbol of their opportunity: Many Democrats believe that the president is vulnerable and that, as Kerry put it in a conversation the other day, “suddenly this is a nomination worth having.”

But the irony is that the presence of so many candidates, particularly fringe figures on the left, may make it more difficult for the Democrats to prevail.

The mere presence in presidential forums of three of the candidates — the Rev. Al Sharpton of New York, former Sen. Carol Moseley-Braun of Illinois and Rep. Dennis J. Kucinich of Ohio — almost certainly will move the Democratic debate to the left, making it harder for the eventual nominee to appeal to swing voters in the general election. “I run well on a sloppy track,” Kucinich said in an interview. “And my message will be so different than anyone else’s — canceling NAFTA and guaranteeing quality health care — that I’ll still be able to stand out.” That’s precisely what worries some Democratic strategists.

In the next several months, former NATO supreme commander Gen. Wesley J. Clark, Sen. Joseph R. Biden Jr. of Delaware and former Sen. Gary W. Hart of Colorado will decide whether to enter the race. They’ll find a lot of companionship along the scenic byways of New Hampshire — but they’ll also find that the important race, the one for dollars and not for votes, is already well under way.

There may be unlimited room in the Democratic field, but there is only so much funding. “The people who give the money will make decisions as to who is viable,” said Kerry. “The money will separate out the candidates, and so will the activists. Merely announcing a candidacy for president does not a presidential candidacy make.” Maybe not, but a lot of his fellow Democrats seem willing to test the theory, and the waters, here in New Hampshire this spring.