Council Bluffs, Iowa ? There will be some extra visitors, perhaps unwelcome ones, hovering in the homes of Iowans during this holiday season.

Whether on television, in daily telephone calls or in an endless string of literature that has deluged Democrats for months, the party’s presidential candidates are barely slowing their campaign operations over the holidays.

The arrival of the holidays doesn’t change the fact that the Iowa caucuses are only 25 days away, the first critical stop in the 2004 Democratic presidential race.

Why else would Sen. John Kerry of Massachusetts plan to ring in the New Year at the community theater in Sioux City?

Each of the leading presidential hopefuls are preparing to spend several days in Iowa before year’s end, a scheduling decision that underscores the importance and intensity of the Jan. 19 caucuses.

But the Christmastime campaigning has touched a nerve with some Iowans — even faithful Democrats — who were hoping for a seasonal reprieve.

“We’re inundated with campaigning the rest of the year. Enough is enough,” said Kay Harms, a retired teacher from Waukee.

The holidays, though, can be a fruitful time for candidates trying to reach undecided voters. And the holiday season provides a bridge to an intense January campaign when candidates will once again try to slow the surge of former Vermont Gov. Howard Dean.

It was the day after Christmas in 1987 when a television commercial opposing free-trade agreements jumpstarted the presidential candidacy of Rep. Richard Gephardt of Missouri, who 16 years later is Dean’s chief rival in Iowa. At the time, Gephardt’s ad was the only one on the air and weeks later, he won the caucuses.

This year, with nine Democrats fighting for the nomination, Iowans have been barraged with a record $4 million in television spots that began over the summer and continue with only a marginal respite during the holidays.

“They don’t want to bother people,” said Dianne Bystrom, a political scientist at Iowa State University. “But on the other hand, people are at home and watching a lot of television.”

Holiday distractions make it difficult to attract much attention, so the candidates have employed creative methods.

Kerry wrapped up a 24-hour Iowa campaign marathon Tuesday, meeting with nurses and factory workers and farmers. Elsewhere, Sen. John Edwards of North Carolina signed copies of his new book, “Four Trials,” in South Carolina. And Sen. Joseph Lieberman of Connecticut worked at a food pantry in New Hampshire, the site of the nation’s first primary Jan. 26.

While Dean planned to spend the holidays in Vermont, some of his aides acknowledged they would be preparing for the Friday arrival in Iowa of up to 500 volunteers to begin an effort to knock on 200,000 doors and reach more than 50,000 voters by phone.