MANCHESTER, N.H. — Sen. John Edwards (N.C.) was the second Democratic presidential candidate Nancy McIninch heard in person. Retired Gen. Wesley Clark was the first, but she might go back another time to check her impressions.

“And I’m thinking about a John Kerry” event, she said of the Massachusetts Senator.

But on Tuesday, McIninch’s short drive from her home in Bedford left her impressed with Edwards’ energy and optimism and with his plans, though she worried how he would pay for them.

Voters like her represent the value of the Iowa caucuses and the New Hampshire primary, because they make the most of frequent opportunities to meet and hear presidential candidates and think about them.

But next week, after Tuesday’s primary here, they will become the exception, as the Democratic race goes before voters scattered among places where at least some candidates have either been frequently (like South Carolina) and places where they have gone rarely (like Arizona) or not at all (Missouri).

The University of Pennsylvania’s National Annenberg Election Survey found last week that 54 percent of registered voters who intend to vote in next Tuesday’s New Hampshire Democratic primary say they know enough about the candidates to make an informed choice.

In the country as a whole, it was only 17 percent. And that’s not just for people who have several weeks to think about it because their primary doesn’t come until March or April or even May or June. (Full details are at the survey’s Web site, NAES04.org.)

In the seven states with primaries and caucuses just a week after New Hampshire — Arizona, Delaware, Missouri, New Mexico, North Dakota, Oklahoma and South Carolina — only 21 percent said they knew enough to make an informed choice. They don’t have much time to catch up on their homework, and it’s a lot less than they used to have.

The process of “front-loading” the primary schedule — advancing the dates of the early contests — has been going on since 1980, but this year it got much worse, because Democrats decided to let other states go one week after New Hampshire, not the five weeks that were allowed in 2000. They had several reasons, such as the hope of uniting behind a candidate early and blunting the attention advantage Republicans got in 2000 by holding exciting contests in those weeks.

But they forgot about the voters. Unlike the members of the Democratic or Republican national committees, most Americans have other things on their mind besides presidential politics. Most of the time they worry about things like their children or their jobs or their sex lives, not what Howard Dean said or meant about Medicare whenever it was.

In the national data from the Annenberg study, only 18 percent of those registered voters who want to take part in Democratic primaries or caucuses said they were following the campaign “very closely.” Sure, the information is out there, if people choose to skip helping their kids with homework to study politics, but that’s not going to happen.

Kathleen Hall Jamieson, director of the survey, pointed to its 2000 results as evidence that the more time people have to pay attention to a race, the more they know. “There is a natural ebb and flow to the process of learning about presidential candidates,” she said. “The closer that one gets to a primary or general election where one gets a chance to cast a vote, the greater the attention paid by those in that area.”

She warned that under the present system, it was likely “that a frontrunner will be designated and some candidates eliminated before most of the country is aware of who the candidates are and the distinctions between them.”

Or, as William Mayer, co-author with Andrew Busch of “The Front-Loading Problem in Presidential Nominations,” observed last week at a Brookings Institution forum: “It ends too soon. There isn’t time for extended deliberation and discussion.”

Those are important arguments about potential risks to a party under this system. And there is strong evidence that front-loading increases the importance of campaign money, and thus helps richer candidates or those like George W. Bush in 2000 — perceived front-runners who had no trouble raising millions.

And then there are the voters. The Annenberg data showed that even among Democrats nationally who had chosen a candidate to back, 79 percent said they knew too little to make an “informed” choice. And even in that 18 percent who say they are following the campaign very closely, a majority said they did not know enough to make an informed choice.

The modern nominating system had its origins in anti-war Democrats’ revulsion at a system where party bosses backed Hubert Humphrey in 1968 although he didn’t enter a single primary to be tested by real voters.

The Democratic Party commission that drew up the new rules in 1970 described its goal as giving “all Democratic voters a full, meaningful, and timely opportunity to participate in the selection of delegates.” Nancy McIninch and her neighbors have that opportunity.

For millions of Democrats, their votes will involve an element of guesswork, votes cast even if the voters think they don’t know enough to make an informed choice. For them, the promise of 1970 will be hollow.

Adam Clymer, who first covered Iowa and New Hampshire in 1972, retired as Washington correspondent of The New York Times last year. He is now political director of the National Annenberg Election Survey.