Bill Bradley stumbled badly in the Iowa caucuses tonight, and the difficulties he encountered in Iowa could continue to plague him as the campaign moves on to New Hampshire.

For Bradley, both entrance poll data and the comments of uncommitted Democratic officials here suggest that he faces serious problems. Voters in Iowa described Gore as a stronger leader with better ideas on the two "big ideas" that are the bread and butter of the Bradley campaign: health care and campaign finance.

In a stinging setback to Bradley, voters selecting those issues as their most important opted for Gore by solid margins: 56-33 on health care and 75-21 on campaign finance.

Bradley could take almost no comfort in the findings here. Voters in every age category backed Gore, even young voters, who were supposed to be a Bradley mainstay. Gore carried every income group by solid margins, except the small segment of Democratic caucus goers making more than $75,000 a year, which Bradley won 49-40. Liberals, moderates and conservatives all voted by wide margins for Gore.

Perhaps most damaging to Bradley, who has sought to present himself as a bigger thinker than Gore and as a man above the pettiness of politics, the entrance polls showed that those who watched debates "very closely" or "somewhat closely" were the most likely to pick Gore over Bradley. Those who said they did not follow the debates closely also favored Gore, but by a slim margin.

Bradley's problems with the caucus goers were echoed in comments by Iowa Democrats, who faulted Bradley for what they viewed as his failure to demonstrate that he is "a fighter" and for running a lackadaisical get-out-the-vote operation in a state where ground organization is crucial.

"You have to give the people a sense that you really want the job, that you will fight for it, so they will know you will fight for them," said Gov. Tom Vilsack (D), who is uncommitted.

Vilsack said a "turning point" in the campaign occurred in a Jan. 8 debate when Gore challenged Bradley to explain how he could have voted against a 1993 amendment giving flood-ravaged farmers another $1 billion. Bradley, looking stunned, replied: "I think that the premise of your question is wrong. This is not about the past. This is about the future."

"That was his chance to show he was a fighter, he should have come back at Gore, 'What have you done for the Iowa farmer?' He didn't," Vilsack said.

Robert G. Tully, the Iowa Democratic chair, said his brother, a former Dubuque mayor, tried repeatedly to become a precinct captain for Bradley but his inquiries, along with those of the party chair himself, went unanswered.

"If I don't get a call back, I hate to think who else didn't get called back," Tully said.

Bradley spent more time (63 days) in this state than Gore (38 days) and outspent Gore on television, $1.9 million to $1.6 million. Just a month ago, Bradley's staff was openly speculating that he could win the caucus fight. Instead, he garnered only 35 percent of caucus goers to Gore's 63 percent--a showing that Bradley said tonight gave him "a little more humility" even as he argued that it exceeded what any other Democratic "insurgent" had done in Iowa.

Until recently, New Hampshire had offered Bradley what looked to be an even better early shot at defeating an incumbent vice president and giving his own bid critically needed legitimacy.

Now, facing the prospect of a second--and potentially debilitating--defeat, the Bradley campaign finds itself under intense pressure to take strong steps to regain momentum in New Hampshire, including sharper attacks on both Gore and the Clinton administration.

The Bradley campaign took a modest step in this direction today. His campaign announced that it is airing a new commercial in New Hampshire in which Niki Tsongas, wife of the late senator Paul Tsongas (D-Mass.), who ran against Clinton in 1992, tells voters:

"Like my husband Paul, Bill Bradley is a passionate supporter of working people, and he too is challenging us with bold vision for America. But what disappoints me now is--just as with Paul--Bill's record is being distorted."

While Bradley is under pressure to sharpen his critique of Gore, his decline in the polls makes him more vulnerable to charges of being a sore loser if he takes a more aggressive posture. "We're damned if we do, and damned if we don't," one Bradley supporter said.

For months, Gore was running behind Bradley in New Hampshire and had even dubbed himself the "underdog" there; now, he leads in nine New Hampshire polls.

Gore's margin over Bradley in polling of New Hampshire voters ranges from just 1 point in one survey to a solid 12 points in two of the polls, with an average lead of 7.5 points.

Jim Duffy, a Democratic consultant who has not taken sides in the contest, said Bradley's early success demonstrated that "there was some real potential there." But, Duffy said, Bradley was "too abstruse, too aloof. . . . People have to like you to vote for you. He had the opening, but he couldn't close the deal."

Dick Morris, who set the strategy for the 1996 Clinton-Gore campaign and now leans more to Bradley than Gore, said Bradley let Gore portray him as someone who would "screw public education and Medicaid. You can't win Democratic primaries with those two hanging around your neck."

Bradley's declining fortunes have forced him to respond to repeated questions concerning how long he will stay in the contest if he loses New Hampshire and Iowa. He has replied that he intends to stay at least through the collection of mega-primaries on March 7, including California, New York and much of the Midwest and New England.

Gore's decisive win tonight, and even a follow-up Gore win in New Hampshire, does not appear likely to produce strong pressure from within the Democratic Party on Bradley to get out of the contest.

Democratic Chairman Joe Andrew said, "the primary process has been good for us. We've gone from 17 down [in trial presidential heats] to 7 down, and the Republicans have been trapped in a debate about abortion while we are discussing health care and education, two issues that work for us. . . . Right now, no action needs to be taken because no damage is being done."