Republican presidential candidates battled toward the finish line of the New Hampshire primary today in a tight race that may have been transformed by an acrimonious party fracas Saturday night.

Sens. Howard H. Baker Jr. and Bob Dole delivered new attacks on George Bush, the perceived front-runner and the man they and Rep. John B. Anderson blame for keeping them out of the Saturday night debate between Bush and Ronald Reagan.

Bush stayed away from the fray in Houston where he is resting for two days before Tuesday's primary.

A buoyant Reagan, more outwardly optimistic than he has been at any time since his loss to Bush in the Iowa caucuses a month ago, for the first time predicted victory.

Asked outside the town hall in Windham whether he would win on Tuesday, Reagan replied through a bullhorn: "Are we going to win? You bet we are and it's all going to depend on you. Get those voters to the polls and we're going to win. But what's more important we're going to win in November too, and turn this country around."

The possible importance of the Saturday debate was underscored by a poll in today's Boston Globe showing the Republican race dead even. Bush led Reagan 35 percent to 34 percent. Baker was third with 12 percent.Anderson was next with 8 percent. Rep. Philip Crane and John B. Connally had 2 percent each, while Dole had 1 percent.

The Democratic race, on the other hand, continued to be lopsided, with President Carter favored by 55 percent of the voters, compared with 30 percent for Sen. Edward M. Kennedy and 8 percent for California Gov. Edmund G. (Jerry) Brown Jr.

And unlike the seven-man GOP battle, in which Crane and Connally are also on the ballot, there has not been anything even remotely resembling a transforming event in the Democratic primary. Carter has campaigned entirely through surrogates, especially his wife, Rosalynn, and Vice President Mondale, while Kennedy has been hampered by unfavorable ratings from voters (48 percent in the Globe poll). Brown's campaign is dead broke.

Clearly the most dramatic event of this primary campaign was Saturday night's stormy debate and the events that preceded it.

How much Bush's actions hurt him was still not clear today, but were widely perceived among the political comunity here as a serious blunder. What most angered the other candidates was that Bush refused to meet with them, and Bush campaign manager James Baker conceded today that this may have been a mistake.

"Looking back on it, I wish we had gone and met with the other candidates before the debate," Baker said today. "But that isn't the way it was presented to us at the time."

Bush and his managers took the position that they had not excluded anyone from anything. They said that the Nashua Telegraph had extended the invitation for a two-man debate, which Reagan claimed as his own after he agreed to pay the cost of it. The Bush camp said that sharing the cost would have pushed Bush over the legal spending limit for New Hampshire.

Jon Breen, executive editor of the Nashua Telegraph, which ran the Saturday debate, came to Bush's defense today.

"The heat that the Bush people are taking from Bob Dole and Howard Baker and the rest is unfair," Breen said. "There is only one person who bears the responsibility [for limiting the debate to a Bush-Reagan affair] and that person is me, representing the Nashua Telegraph. The Bush people made it clear to us that they were willing to open it up [to all Republican candidates] but that the decision was up to us . . . We said no. We were not about to run a cattle show."

The key question about the Saturday debate was not who won or lost, but who saw it. NBC carried nine minutes of the affair on its Saturday night Prime Time show but a basketball game preempted this program in New Hampshire. Other television coverage was relatively scant, though the debate was carried live on radio.

In Peterson's General Store in Canterbury, a rustic gathering place 10 miles north of Concord, where townsfolk talk and buy papers after church on Sunday morning, practically no one had heard of the debate. However, those who did didn't think much of Bush agreeing to exclude other candidates from the affair.

Jamie Hollis, a 31-year-old Bush supporter and investment counselor who had come to the store to buy a soft drink and smoke a cigarette, found Bush's action surprising.

"it disturbs me he wouldn't let the other guys in," Hollis said. "I always thought George Bush was above that. Politically, I can understand why he would do it, but I thought George Bush was above that kind of politics."

However badly Bush and his managers may have handled the politics of the moment, their strategy has been for Bush to try to deemphasize attention paid to any candidate except himself and Reagan.

As Bush's well-regarded pollster, Robert Teeter of Detroit, sees it, Bush must hold Baker under 20 percent and the combined candidacies of Anderson, Connally Dole and Crane to another 20 percent to have a chance of winning.

"Reagan's core strength, which is very hard, is at least 30 percent and maybe a couple of points higher," said Teeter. "If the other candidates reach 40 percent combined, there won't be enough votes left to win."

In campaigning today, most of the other candidates continued to bang away at Bush. Appearing on "Meet the Press," Baker called the refusal of the Nashua Telegraph and Bush to let him participate "the rawest political act I've seen in 15 years of politics." If Bush is the front-runner said Baker, "He wears the crown with little grace."

At a Manchester news conference, Dole said it was the second time he'd been pushed out of the way by Bush, a reference to President Nixon's replacement of him with Bush as Republican national chairman in 1973.

Elizabeth Hager, Anderson's New Hampshire chairman, said that Bush showed "incredible arrogance" in refusing to meet the other candidates.

But Eugene Shannon, the Crane coordinator in New Hampshire, said it looked to him as if the event were "an orchestrated thing" by Reagan, who he blamed for not telling the other candidates that the Nashua Telegraph hadn't agreed to accept them in the debate.

This view also prevailed in the Bush camp. The candidate's New Hampshire press secretary, Sarah Browning, said Bush supporters were calling in to complain that their man had been "sandbagged" Saturday.

Whatever the verdict on the debate, Bush was not around to hear it. He left the state because of the belief of his New Hampshire campaign Manager, former governor Hugh Gregg, that a candidate's absence allows his organization to concentrate on get-out-the-vote efforts.

Bush has not campaigned in New Hampshire, except for last week's two debates, since last Monday. Reagan is campaigning hard in this state, and his supporters are enthusiastic. One campaign aide said of the Reagan entourage: "I haven't seen anyone's feet touch the ground."

The Reagan camp was hoping that the fallout from Saturday's debate would be to reinforce the impression that Bush is an "elitist."

Gerald Carmen, the New England regional coordinator for Reagan, has been portraying Bush as a well-heeled, upper-class preppie, whose success derived from the money and position of his father, the late senator Prescott Bush of Connecticut. In contrast, the Reagan campaign has celebrated the humble Midwestern origins of wealthy former California governor Reagan, son of an Illinois shoe salesman.

In the Globe poll, Reagan had nearly 2-to-1 support from Republicans with less than $10,000 annual income and a substantial lead among voters who made less than $20,000. Above this figure, the pattern reversed, with Bush enjoying his biggest margin among voters who make $30,000 annually or more.

It is possible that Bush reinforced this image on Saturday night as he sat with seeming indifference on the stage of Nashua High School while four Republicans excluded from the debate -- Anderson, Baker, Dole and Crane -- stood in the back and waved to the crowd. Reagan made it a point to shake each man's hand, while Bush neither looked at nor spoke to the other candidates.

In the Democratic race, the main burden facing the Carter forces has been to prevent a feeling of overconfidence that could produce a stay-at-home reaction.

Every poll in the past month has shown the president far ahead of Kennedy and Brown, but Gov. Hugh Gallen, the leading Carter supporter, has doggedly insisted that the race is really "very close."