BARTLETT, N.H. — Stop by the side of the road on an afternoon like this, and the splendor of this state sits before you in a wide panorama. To the north is Mount Washington, the regal symbol of the state. To the northwest is the Willey Range, its customary mystery stripped away as the peaks provide rare peeks of their own. On a day like today, this green state has a canopy of dark, dark blue. If you were a meteorologist, you might say that what you were seeing was a high ceiling.

But on other days, the brooding days that make this state a forbidding fortress of mountains, protected by a moat of storms, the summits are not clear, the sky is not bright. On these days the state frowns, its brow is furrowed, and heaven help you if you think your boots will be dry by midmorning. On these days there is a very low ceiling.

It may be a peculiarly New England turn of mind that makes meteorology a metaphor, but it is also a peculiarly New England turn of mind that makes presidents. The New Hampshire primary is mostly a mood ring. If New Hampshire is in a rebellious mood, the rebels prevail, which is why Patrick Buchanan will always have a place in the state’s political history. If New Hampshire has a sunny disposition, the contender with the bright outlook will have bright prospects. That’s why Bill Clinton was a two-term president.

So the question for this morning’s consideration is whether the ceiling is high or low. This is not an idle topic for a summer’s idyll in the mountains. It is perhaps the most important question facing Senator Clinton as she prepares a campaign for the presidency here in these hills, which Daniel Webster always considered a character test for men — and now is one for women. Because before long New Hampshire, which has had strong females in the state legislature and already has had a female governor, Jeanne Shaheen, is very likely going to test a female presidential front-runner.

That’s where the ceiling question comes in. It’s not the first time ceilings have been important in American politics. Senator Kennedy was for years a serious threat for the presidency, but he had a ceiling. There was a definite, definable, and determined group of people who would never, ever, vote for him for president, and my guess is that the figure was about 45% of the American people. Think of it this way: Nearly half of Americans wouldn’t have an open mind about anything Mr. Kennedy said.

We don’t know what the Hillary Clinton ceiling is, but we have some hints. Just this month, the Washington Post-ABC News Poll asked Americans whether they would consider voting for Senator Clinton for president “or would you definitely not vote for her.” The wording of the question is significant. It tells us, with a little arithmetic, the size of the electorate that is walled off from any Clinton appeal.

It turns out that 42% of the public, according to this sounding of opinion, would definitely not vote for Mrs. Clinton. There are other findings of significance. Only 1% of the public had no opinion on the question. That tells us that the New York Democrat is well-defined in the public’s eye, both an advantage and a disadvantage. She doesn’t need to spend lots of time and money getting people to know that she exists. But she also doesn’t start with the clean, fresh slate that some candidates — Jimmy Carter and Bill Clinton are good examples — used with such deftness in their New Hampshire campaigns.

The fact that 42% of Americans simply won’t consider her for president is a very worrisome sign for Senator Clinton. It means that she can focus her appeal only on 58% of the electorate. That gives her very little room to maneuver, because the public’s willingness to consider a presidential candidate is the oxygen of a national campaign. Without an open mind, people cannot come to the conclusion the old hero in Willa Cather’s now-forgotten story “Neighbour Rosicky” reached about his daughter-in-law: “But now he knew Polly would make a fine woman after the foolishness wore off.”

The result: In a general election, Senator Clinton has to win the support of almost everybody who doesn’t find her repugnant. She’ll be the only candidate in the field two years from now with that challenge.

Put another way: Her Democratic rivals have more elbow room politically than the front-runner. A good example is Governor Tom Vilsack of Iowa, who can only dream about having the name recognition that Mrs. Clinton possesses. But 100% of the electorate, theoretically at least, is open to a Vilsack candidacy, if only they knew who he was. His potential appeal is far greater than Senator Clinton’s.

This is not to say that Mrs. Clinton is cooked. She’s not.This same poll shows that 68% of the public thinks she is a strong leader. That’s about 68 percentage points above the public’s perception of Mr.Vilsack, who hasn’t had a chance to tell people in New Hampshire and elsewhere what he’s accomplished in Iowa.

But only half the public (about 52%, according to this poll of 550 respondents) thinks she is honest and trustworthy. That’s clearly her challenge, and that (along with skepticism about a female president, very hard to measure in a poll) accounts for the ceiling problem.

Why does she have a trust problem? Easy answer, which is why the solution is so hard. Liberals think she has become too conservative, and conservatives think she is too liberal. And in the back of everybody’s mind are the ethical questions surrounding her husband’s presidency that haven’t quite vanished — ethical questions that always had a Hillary factor, sometimes fairly, sometimes quite unfairly.

So on a brilliant summer’s day, as Senator Clinton glides through her re-election campaign in New York and girds for a presidential run, it is useful to contemplate those mountains visible from the side of the road. They sure are beautiful. They sure are imposing. They offer challenge, they prompt foreboding. But the biggest factor in how they look from ground level is the ceiling. It’s something that affects all the visitors to this state, the tourists with their sturdy tent stakes and the touring candidates with their big political stakes.