Ten months ago, Senator Hillary Rodham Clinton went to East High School here on her first trip to Iowa as a presidential candidate and laid out a case for her candidacy to a cheering crowd in a packed gymnasium.
Mrs. Clinton returned to East High School late last week. But the crowd was much smaller and more sedate. And rather than discussing her candidacy, Mrs. Clinton explained the caucus process and showed a video titled “Caucusing Is Easy.”
The video was directed at voters who might be intimidated by the complicated Iowa caucus process. But the reassuring message might as well have been intended for the candidate herself.
Though she maintains a solid lead among Democrats in most national polls, Mrs. Clinton is showing signs of vulnerability, with her margins narrowing in the early voting states and her main rival for the nomination, Senator Barack Obama, taking her on more aggressively.
Nowhere are her problems more on display than in this state, where success lies in building a person-to-person network of supporters. And nowhere is the Clinton campaign — which to some Iowans had appeared ignorant of the political subtleties, if not arrogant about them — working more urgently to recalibrate and head off defeat as the Jan. 3 caucus approaches.
“Here’s the bottom line: They had not worked this state,” said Teresa Vilmain, the Iowa state director, who was brought in here in a quiet campaign shake-up that took place early last summer, when Mrs. Clinton first saw signs of problems here. “We had a lot of ground to cover. It’s a challenge.”
Iowa, where Mrs. Clinton and her husband do not have the advantage of having run a primary campaign, as they have in New Hampshire, is a place that has appeared to frustrate the Clinton political operation from the day she arrived here. Bill Clinton never competed in Iowa caucuses; the state was effectively conceded to Senator Tom Harkin of Iowa in 1992, and Mr. Clinton was unopposed in 1996.
A poor showing in this state on Jan. 3 could have ramifications in New Hampshire five days later, where polls suggest growing support for Mr. Obama, particularly among independent voters, who can vote in either party’s primary.
In an interview, Mrs. Clinton said she had become increasingly grounded in the ways of Iowa, though she acknowledged her concern about her campaign here.
“I always thought that Iowa would be a challenge,” she said, “and I’m personally really pleased with how far I’ve come, never having done this with Bill. I’ve really been working to understand what was necessary to run a competitive campaign.”
The signs of Mrs. Clinton’s concern have been on increasing display here in recent days as the campaign has been moving rapidly to make up for earlier mistakes.
Her aides said she had largely cleared her schedule this week to prepare for the Democratic debate on Thursday sponsored by The Des Moines Register, the final encounter here among all the candidates, which they now view as one of their final opportunities to shift the momentum back to her favor.
Needing a strong performance to head off inroads made by Mr. Obama and tamp down questions about whether she is too calculating, she is reviewing past Register debates and issues of particular importance in Iowa, and hoping to win The Register’s endorsement, the aides said. (She went from East High School to downtown Des Moines for a private dinner Friday evening with David Yepsen, the influential Des Moines Register columnist, who has repeatedly questioned whether Mrs. Clinton appreciated the nuances of the state.)
The Clinton campaign has doubled its weekly television advertising spending from $400,000 last week to $800,000 this week. Beyond that, most of her senior staff has moved from the campaign’s national headquarters in Virginia to a windowless cluster of desks in Mrs. Clinton’s headquarters in an office complex on the east side of Des Moines. Over the next few days, Howard Wolfson, the face of the Clinton war room, is planning to drive out here from Washington. (Mr. Wolfson does not like to fly.) Patti Solis Doyle, the national campaign manager, has moved to Des Moines.
Mrs. Clinton has begun displaying a level of personal interest in the details of the campaign here that is unusual for even a presidential candidate named Clinton. After every stop, Mrs. Clinton questions her advisers about how many attendees have signed the pledge cards that she has come to learn are an integral part of nailing down supporters.
At a time of growing tension in Mrs. Clinton’s campaign, her aides described former President Bill Clinton as increasingly frustrated that his wife’s campaign has not fought back even more forcefully against efforts by Mr. Obama and former Senator John Edwards to raise questions about Mrs. Clinton’s character. They said that Mr. Clinton had warned for weeks that they were taking a toll on his wife’s candidacy.
Mr. Clinton, they said, is still confident that his wife can regain momentum if her campaign presents her message — and particularly criticism of Mr. Obama — more sharply. He took matters into his own hands Monday, campaigning at four events across Iowa to deliver that message: that Mrs. Clinton was a “change agent.”
In a sign of internal strains, some of Mrs. Clinton’s associates said they thought Mr. Clinton was struggling to make the adjustment from principal candidate to supportive spouse. In one example of this, Mr. Clinton asserted in Iowa last month that he had been against the war in Iraq “from the beginning,” a statement more absolute than his public statements at the time. His remark produced a round of criticism that the Clintons too frequently parse their positions for political gain.
It is in the interest of Mrs. Clinton’s advisers to reduce expectations for their candidate. Still, their assessment that Mrs. Clinton was having trouble mastering the political intricacies of this state was echoed by Democrats in other campaigns, and reflected by the sometimes tin-ear quality of the Clinton campaign here.
On her first trip here last January, one adviser said, Mrs. Clinton repeatedly expressed frustration, confiding to one associate that she “had no feel for the place.” She responded with bewilderment when informed that she should not assume that she now had the support of an Iowa Democratic leader even after spending 40 minutes over coffee with him.
“It’s a unique and difficult dynamic,” said Tom Vilsack, the former Iowa governor who has become one of Mrs. Clinton’s top Iowa advisers.
Mrs. Clinton spent much of the early part of the year working huge rallies in the state’s major news media markets in the belief that the coverage would reverberate into the more sparsely populated areas. But that is not the way things work in Iowa.
Mr. Obama and Mr. Edwards methodically worked rural areas, appreciating the importance of personal appeals to small groups of voters. Over the last six weeks, Mrs. Clinton has opened satellite offices and intensified her visits to rural Iowa.
Most recently, Mrs. Clinton has struggled to find the right tone to use in attacking Mr. Obama in a state where voters have been known to recoil at negative campaigning. Some of her attacks on Mr. Obama, including one in which she questioned his character and another where her staff mocked him for writing a kindergarten essay saying he wanted to be president, were described even by some of her supporters as clumsy.
Mrs. Clinton’s advisers said they would continue at least some form of attack on Mr. Obama, even at the risk of allowing Mr. Edwards to gain ground by presenting himself as above the fray. Mrs. Clinton’s aides said they were far more worried about Mr. Obama marching out of Iowa with a victory than they were about Mr. Edwards, who has far less money and lacks a strong base of support in New Hampshire.
Jeff Zeleny contributed reporting.