NASHUA, N.H., FEB. 10 -- Vice President Bush hurried back to New Hampshire today for an all-out effort to reverse a political slide that has moved Sen. Robert J. Dole (R-Kan.) to within striking distance of him in the nation's first presidential primary here next week.

Overnight polling Tuesday by The Washington Post and ABC News showed Dole closing the gap between him and Bush to 4 percentage points, with Bush clinging to a 33-to-29 percent lead. The results represent a net gain of 6 points for Dole in the first 24 hours after he won the Iowa Republican caucuses and Bush finished third behind former television evangelist Pat Robertson.

Rep. Jack Kemp (R-N.Y.), with 12 percent, was a distant third in the overnight tracking poll, which showed Robertson's support growing from 6 percent to 9 percent.

While Robertson is not thought to pose a direct threat to Bush or Dole here, there is a growing consensus among political operatives in the state that he could overtake Kemp and finish third in Tuesday's primary. Such a result would effectively end Kemp's campaign, which is already reeling, and give Robertson another boost before the southern-dominated March 8 "Super Tuesday" contests.

Former Delaware governor Pierre S. (Pete) du Pont IV had slipped to 7 percent support and former secretary of state Alexander M. Haig Jr. to 2 percent, according to the poll.

Bush, in danger of two consecutive losses that would transform Dole into the clear Republican front-runner, hastily rearranged his schedule and revamped his campaigning style virtually overnight. He returned to New Hampshire a day earlier than planned to attend a GOP dinner with the other Republican candidates here tonight. And he dropped a scheduled day in the South this weekend to concentrate all of his time and energy on the crucial New Hampshire primary. A crowd of campaign aides, assigned to states other than New Hampshire, got new marching orders today: Take the first plane to New Hampshire.

There were no fireworks at tonight's Nashua GOP Lincoln Day dinner as each of the candidates stuck closely to his campaign themes and avoided assaults on rivals.

Bush began the last-minute efforts to stem the tide tonight with live appearances on the NBC network news program and interviews with Boston's three main television stations, which reach most New Hampshire voters. He has also purchased 30 minutes of time on WBZ-TV in Boston this weekend for an "Ask George Bush" program in which he answers questions from members of an audience. New commercials that take on Dole more directly are being prepared.

The Bush campaign displayed a change in style and tone in the wake of the Iowa caucuses. Bush made an unscheduled stop at a shopping mall in Nashua. And aides said he will adopt a more informal approach to his campaign, which has been marked by carefully planned events.

Bush also endorsed a "flexible" spending freeze to reduce the federal deficit, a plan apparently similar to Dole's call for a freeze with some exceptions for programs benefiting low-income Americans. Previously, Bush has stressed the line-item veto as a means to reduce the deficit, but today he mentioned it only in response to questions.

Dole, meanwhile, shifted from weeks of tough direct attacks on Bush to carefully sidestepping invitations to criticize him. He denied that a statement that presidents and presidential candidates should make themselves frequently available to the news media was a veiled criticism of Bush for not discussing his role in the Iran-contra affair.

"I don't want to get into a quarrel with the vice president," Dole said. "He's a good man, and we're up here running at a high level."

Dole, whose aides said they are bracing for Bush attacks, also denied that his emphasis on leadership as a campaign issue is an implicit suggestion that Bush is not a leader.

"I'm talking about Bob Dole and his record of leadership," he said.

Dole's style today and his refusal to criticize Bush reflected confidence within his campaign that the political dynamic here is running his way. According to sources, the Dole campaign has also decided at least temporarily not to use a television commercial -- entitled "Footprints in the Snow" -- that suggests that Bush has left few marks in his long career in public office.

"The environment of this election is such that I don't think we have to do anything dramatic to change it," said Thomas D. Rath, a key Dole strategist here. He added Dole's main task in the next few days is "to look and act like a guy who is ready to be president of the United States."

One clear danger for Bush is that his third-place finish in Iowa, coupled with Robertson's surprisingly strong showing, will convince mainstream New Hampshire Republicans that only Dole can turn back the Robertson challenge and retain the White House for their party. That is a perception that the Dole campaign would like to encourage.

The Iowa results "make the point that this man is vulnerable electorally," Rath said. "Regular Republicans always had doubts about the vice president's electability. They want a candidate who can win."

Bush's New Hampshire lead over Dole was eroding even before Iowa Republicans caucused Monday night, according to earlier Post-ABC polls.

The latest overnight tracking survey showed Dole broadening his base among conservative Republicans here, while Bush has been ineffective in increasing his share of moderate GOP support.

Dole also appears to have been helped dramatically by women. He surged from a 13-point disadvantage against Bush with female voters before the Iowa caucuses to a 4-point lead among them in Tuesday's poll.

Richard Wirthlin, Dole's pollster, said the campaign's polling shows Dole pulling to within 5 to 7 points of Bush.

"It's quite clear to us that this is a very winnable race," he said. "We aren't home free yet, but it started before Iowa."

In a state where President Reagan remains highly popular, both Bush and Dole have stressed their close ties to him. Neither showed any inclination to steer away from that course today. But according to David W. Moore, director of the University of New Hampshire's polling service, Dole's emphasis on what he has accomplished for Reagan as Senate Republican leader appears to be more effective than Bush's repeated assertions of loyalty to the president.

Moore said, "Dole does it much more subtly. He's got his own message. Bush's only message is that he's been vice president."

Moore said that in a UNH poll concluded Feb. 3 almost 20 percent of Bush's supporters said they would not necessarily stick with him if he did poorly in Iowa. In that poll, 29 percent of Kemp's supporters said they might abandon him if he did not do well in Iowa, he said.

According to GOP sources, Kemp's poll Tuesday night confirmed his vulnerability to a surge by Robertson and his almost hopelessly distant position behind both Bush and Dole. The poll showed Bush leading Dole, 32-to-27 percent, and Kemp at 11 percent, the sources said. They said Kemp has lost 6 points over the last four days.

Kemp cannot count on much news media attention to offset his slide in the polls and his financial problems. Television and newspaper accounts of the the GOP race today were dominated by the Bush-Dole showdown and Robertson's insurgency.

"It's likely that Kemp will get lost" among the three others, Moore said.

Campaigning today, Kemp aimed his heaviest fire at Dole, whom he accused of having "led the fight for the five major tax increases in the last five years. "When he talks about the future, it's time to grab your wallets," he said.

Bush, however, commands intense media attention and has the financial and organizational resources that his aides said today can halt Dole's drive.

"There's a firestorm now of sorts," said Ron Kaufman, Bush's Northeast political director. "That's the nature of the beast in Iowa." But he added that "the plan from day one was to build a good solid organization that can deliver George Bush votes. . . . I feel very comfortable that this is when an organization pays off."

A key part of the Bush organization here belongs to his state chairman, New Hampshire Gov. John Sununu (R). At a news conference today, Sununu weighed into the battle, accusing Dole of inconsistent positions on a possible oil import fee, an unpopular idea in frigid New England.

"If I didn't like Sen. Dole, I'd say he's being deceptive," Sununu said. "But I do like him, so I'll just say he's waffling."

Staff writer David Hoffman, polling director Richard Morin and polling assistant Kenneth John contributed to this report.

The Washington Post-ABC News Poll was based on telephone interviews conducted Tuesday with randomly selected registered voters in New Hampshire who said they plan to vote in the state's presidential primary next Tuesday.

This survey is the first in a series of comparable "tracking polls" that will be conducted by The Post and ABC News through primary day. Tracking surveys, in which small nightly samples of voters are combined over several days, provide a moving picture of a campaign. Such surveys are widely used by private pollsters to monitor shifts in voter preferences.

Findings were based on 403 registered Democrats and independents who said they will vote in the Democratic presidential primary and 404 registered Republicans and independents who said they will vote in the Republican primary.

Figures were adjusted slightly to conform with Census Bureau estimates for the population with regard to age, education and gender. Results were also adjusted to give greater weight to people who said they are certain to vote.

In addition, slight differences in the way the Post and ABC News adjusted the overall sample might result in minor differences in the results reported by each organization.

The margin of sampling error is plus or minus 5 percentage points for results reported by party. Sampling error is only one of many potential sources of error in this or any other public opinion poll.