Five months before the nation's first primary, former New Jersey senator Bill Bradley has virtually pulled even with Al Gore in New Hampshire, turning a once lopsided advantage for the vice president into a fiercely competitive contest.

Three recent polls confirm how much gloomier things are for Gore today, with Bradley closing to within 4 to 7 percentage points of the front-runner. What has happened in New Hampshire is, in microcosm, the story of how the former basketball star has turned the competition for the Democratic nomination into a fight to the finish.

When the presidential campaign began last winter, Gore seemed to have most of the advantages here. He had the power of incumbency and the support of a president who, however controversial, was popular among Democratic activists and had an extensive network already in place here. Gore's New Democrat credentials, meanwhile, offered him the opportunity to bid for support of the "New Economy voters" and political independents, who often play a crucial role in this idiosyncratic state.

But over time those seeming advantages have been eroded, as Gore has struggled to capitalize on the institutional Democratic Party support available to him, while Bradley has had success reaching directly to rank-and-file Democrats and especially to independents.

Much can change between now and February, but this is not the campaign the vice president had hoped for. "They wanted a coronation rather than a fight," Andrew E. Smith, director of the University of New Hampshire Survey Center, said of the Gore campaign. "Now they've got a fight."

A Bradley victory in New Hampshire would severely wound the vice president and set up crucial contests a month later in New York, where a new poll to be released today shows a dead-even race, and in California, where Gore enjoys a larger lead. Even if Gore survives, his supporters fear he would be weakened in the general election.

If there is any silver lining in all this for the vice president, it may be that the element of surprise has been eliminated from Bradley's strategy here. The former New Jersey senator, running an insurgent's campaign, will not be able to sneak up on Gore in the final week of the New Hampshire contest, as Gary Hart did against Walter F. Mondale in 1984. That also means more scrutiny of Bradley from voters and the news media -- both on what he says he would do as president and on his record in the Senate.

But that may be the only good news the vice president and his campaign team can draw from the unexpectedly early narrowing of the Democratic nomination fight in New Hampshire. "The dynamics of this race are such that Bradley's in extraordinarily good shape," said one New Hampshire Democrat who is supporting Gore and who asked not to be identified.

"This is a wake-up call for the entire campaign," a senior Gore adviser conceded. "That's the positive thing. You'll see us getting into high gear in New Hampshire. We'll be fighting it house by house, block by block."

The sharpened lines in New Hampshire have forced a change in the Gore strategy. Up to now, the vice president's campaign has attempted to ignore Bradley and to draw contrasts with Texas Gov. George W. Bush, the GOP front-runner. That is no longer the case.

"We believe Bradley has had a bit of a free ride with the media and that it's time to start to point out the differences," said Joe Keefe, a former New Hampshire Democratic Party chairman and a Gore supporter. "We also think Bradley is trying to run to Gore's left and reinvent himself a bit to appeal to the liberal, insurgency bias among New Hampshire voters."

"Voters know little about him," a top Gore official said. "When the inconsistencies are pointed out, it will be uncomfortable for him."

A week ago, Gore surrogates criticized Bradley for supporting school vouchers as a senator, forcing Bradley to say he did not believe vouchers represented a national solution to the problems of public schools. More attacks are likely.

Gore supporters in New Hampshire appear defensive, protective of their candidate and anxious to point out the disadvantages of campaigning as a sitting vice president. Over time, they say, Gore will begin to connect with the demanding voters of New Hampshire.

"It's very hard when you're vice president to run a grass-roots campaign," said Bill Verge, the Rockingham County Democratic chairman and a Gore supporter. "He's done a better job than I expected him to -- better than anyone has in the past."

Gore has a clear advantage in endorsements and resources. Gore, for instance, has a strong relationship with Democratic Gov. Jeanne Shaheen, the most popular politician in the state, and, in the absence of an outright endorsement from the governor (which most Democrats expect will come later), Gore signed up her husband, Bill Shaheen, as his state campaign chairman.

On issues, Gore also has the right kind of record -- support for labor and civil rights issues -- and background -- a keen interest in the environment and in technology issues -- to appeal to traditional Democrats and to the New Economy voters in New Hampshire.

But over time, none of those advantages have done much to stall Bradley's progress, both with Democrats and with the increasingly important independent bloc of voters.

"We always felt that Bill would do well here," said Mark Longabaugh, Bradley's New Hampshire coordinator. "But because the establishment was with Gore, we [decided we] would go straight to the voters."

In July, the Bradley campaign devoted a week to canvassing Democratic and independent voters in New Hampshire. The Bradley volunteers knocked on 35,000 doors in 22 towns and cities and distributed 100,000 pieces of literature. Even Gore supporters say the canvassing was effective. "People came to my doorstep a couple of times," Keefe said. "I don't think they singled me out. I think it was real. They've impressed me so far."

Over time, Gore's establishment-driven campaign has come to appear too top-heavy to his supporters in New Hampshire, and they see Bradley's ability to move without a big entourage as a huge advantage in a state where face-to-face contact with voters is crucial.

"Bradley's campaign has a lot of young people, and Gore's campaign is Washington," Verge said. And Gore's association with President Clinton has become a burden as well as a boost. "It's a real dilemma," said one Gore loyalist. "So many people are so sick of Clinton, so embarrassed by him."

Among Democrats who admire Clinton, Gore runs strong, but among those who do not, Bradley is the favorite. The latest WMUR-TV poll showed that among voters age 65 and older -- a group with a less favorable view of Clinton -- Bradley has a substantial lead over Gore.

Bradley also appears to have an edge among independent voters, although two recent polls vary significantly on just how much of an advantage he has. A Boston Globe poll showed independents supporting Bradley 51 percent to 31 percent. The WMUR poll showed Bradley's lead within the margin of error, 44 percent to 42 percent.

The sharp narrowing of Gore's overall lead in New Hampshire foreshadows a long and difficult fight for both campaigns.

Gore's New Hampshire organizers say the new polls, while not helpful, may spur greater intensity among their supporters. "It gets our supporters up and active," said Nick Baldick, the vice president's New Hampshire coordinator. "We've gotten going."

Gore supporters also said that Bradley will fare worse the more voters compare the two candidates. "Once it becomes a one-on-one contest, where these two are compared on their ideas and their performances, that will favor the vice president. Anyone who watched Bill Bradley play in the NBA recalls that he was never a very good one-on-one player," said a Gore adviser.

Bradley supporters acknowledge that their candidate faces a difficult period in the next few months as he begins to lay out his policy prescriptions and attempts to parry the vice president's attacks. "How he handles this is important," said John Rauh, who along with his wife, Mary, a former Democratic candidate for Congress in New Hampshire, is among Bradley's most prominent supporters here.

But Sue Calgary, a top Bradley organizer and a veteran of Hart's 1984 campaign, said the change in the polls will not change the character of Bradley's campaign. "We still are the insurgent candidacy," she said, "when you consider the vast resources of the vice presidency. It didn't change anything for us when we saw those polls."