With few exceptions, Republican and Democratic pollsters and political analysts believe that the breakthrough on an arms-control agreement with the Soviet Union offers the prospect of salvaging the damaged reputation of the Reagan administration and improving GOP chances of retaining the White House in 1988.

"This could restore faith and trust in the presidency more rapidly than anything else," said presidential pollster Richard B. Wirthlin, who has scheduled a survey of public reaction this week.

Frank Greer, a Democratic campaign consultant, agreed that it "removes one of the major levels of concern that people have about the Republican Party, that it can't be trusted with arms control. It removes an issue that has benefited the Democrats."

But Greer argued that Friday's announcement of an agreement in principle to destroy all intermediate- and shorter-range nuclear missiles is probably not "enough to change the {anti-Republican} trends we are seeing in every poll." And others cautioned that a serious internal Republican battle over the treaty -- signaled by the criticism of several conservative GOP presidential contenders -- could let the Democrats argue that they are the party that will follow through on President Reagan's initiative.

"Any opposition by the Republican right will send disastrous signals to the American electorate that the Republican Party cannot be trusted with arms control," Geoff Garin, a Democratic pollster, argued. "The Democrats have had a problem of being seen as too soft on defense . . . . {If the GOP right wing} opposes the treaty, they {the Republicans} become the kooks."

But most political insiders, regardless of party, see the prospective intermediate-range nuclear forces (INF) treaty and the fall summit between Reagan and Soviet leader Mikhail Gorbachev as the biggest foreign policy achievement of the Reagan years, one that could wipe out much of the lingering odor of the Iran-contra affair.

"This is going to be the monument to Ronald Reagan's presidency," Democratic consultant Robert Squier said. "They have found it."

Robert Teeter, whose Detroit polling firm counts Vice President Bush among its clients, said the arms-control breakthrough is perhaps the only achievement "big enough and significant enough" to offset the damage the administration received during the past 10 months on its handling of foreign policy. "Fighting drugs or improving education wasn't going to do it," Teeter said.

In the wake of the Iran-contra affair, public approval of Reagan's performance as president dropped from a second-term peak of 70 percent in April 1986 to a consistent range of scores near 50 percent through the most recent Washington Post-ABC News poll in August. Approval of Reagan's handling of foreign affairs dropped to a low of 33 percent last March and gradually recovered, coming back to a still-low 42 percent in August. Several polls, including The Post's, have shown the Democrats leading the Republicans as the party more people trust to handle foreign policy and questions of peace.

Two other Republican pollsters, V. Lance Tarrance and Linda Divall, commented that the treaty and what it symbolizes may be able to dominate the news for months -- with the prospective summit signing ceremony and then the Senate debate on ratification. "It switches attention to the high ground of U.S.-Soviet relations," Divall said, "and reduces the fears of nuclear war."

"It fills the crucial need for a Republican administration to finish on an upbeat note," Tarrance agreed.

A caution expressed by several Republicans is that the agreement may face initial skepticism -- particularly from Reagan's fellow conservatives, who share his often-expressed distrust of the Soviets. "A lot depends on who supports him and who attacks him," Teeter said.

The announcement was greeted warmly by Bush, who praised the proposed agreement as one that "will verifiably ban an entire generation of these awesome weapons," and, with some qualification, by Senate Minority Leader Robert J. Dole (R-Kan.). Both men are expected to be involved in the Senate ratification fight. Rep. Jack Kemp (R-N.Y.), Marion G. (Pat) Robertson, former Delaware governor Pierre S. (Pete) du Pont IV and former secretary of state Alexander M. Haig Jr. voiced either strong reservations or outright opposition.

Robertson yesterday accused Secretary of State George P. Shultz of "pushing this agreement without adequate safeguards." He said that any INF accord "should be linked to the reduction of Soviet conventional forces. Without such safeguards, we risk decoupling our European allies from the United States while laying them open to overwhelming Soviet conventional military superiority."

Haig said he opposed the INF accord because "it makes conventional war in Europe more likely. . . . throws the defense of Europe more heavily on our strategic deterrent . . . {and} ignores aggressive Soviet behavior in Afghanistan and elsewhere . . . . "

In some cases, political positioning for the Republican primaries may have had as much influence as national-security theories. "There has to be a contrast to get people out to vote {in primaries}," said Tarrance, an adviser to the Kemp campaign.

Dole indicated in an interview Friday that the prospect of playing a prominent role in the ratification fight is an extra inducement for him to remain as the Senate's Republican leader after he becomes a declared candidate this fall. But Divall expressed a widespread view when she said that "Bush is probably the biggest beneficiary because he's part of the administration."

"Reagan at 60 {percent approval} is a lot better for us {the Bush campaign} than where he's been," Teeter said.

Both Wirthlin and Teeter argued that signing and ratification of the treaty might be a large enough even to tip the country out of the negative view of its prospects almost all the national polls have been finding -- and thereby deny the Democrats the "time for a change" theme almost required for an opposition party presidential victory.

Democratic pollster Harrison Hickman downgraded the Teeter-Wirthlin argument, countering: "That's a double bank shot. That flies straight in the face of what people vote on in the general election, and that is bread and butter."

Other Democrats held conflicting views over the political implications of the INF accord, although most agreed that it will significantly alter the content of the debate in the primary and general elections.

"It gives them {the Republicans} the opportunity both in arms control and in expending the message to Central America to say that the only way you get peace, the only way to get a treaty, is to stand tough, and that is what differentiates" Democrats from Republicans, Paul Maslin, a pollster who is Hickman's partner, said.

"Their debate is going to be that the Democatic Party wants peace, but it can't get it because the Democrats are not willing to make a commitment to American strength that forces Gorbachev to the bargaining table," Maslin added.

The Democrats' will attempt to counter this with the claim that their party is more deeply committed to the achievement of peace, better equipped to "maintain strength while at the same time avoiding an acceleration of the arms race," Maslin said.

"Democrats may be able to argue that if Reagan has made a treaty, we {the Democrats} are better able to keep it," he added. Garin and Greer separately contended that the achievement of a major arms-control treaty is likely to lessen the pressure on Democratic presidential primary candidates to adopt anti-defense, anti-Reagan foreign policy stands that might encourage the electorate to see the Democratic field as weak on defense.

"It takes away the need for Democrats to appear anti-defense by appearing to be in favor of reducing the arms race," Greer said.

At the same time, Greer argued, a quieting of the arms-control debate will "allow the Democrats to concentrate on {domestic economic policy} issues they can win on."

William Carrick, manager of the Democratic presidential campaign of Rep. Richard A. Gephardt (D-Mo.) said:

"Anything that keeps the party from getting in a no man's land on defense issues is probably positive for the general election."

Fred Martin, manager of the presidential campaign of Sen. Albert Gore Jr. (D-Tenn.), said: "We are for this, we congratulate the president, but I don't see any change in the political equation because after all these years of missed opportunities, the Republicans have finally come around to the argument of their political opponents, that arms-control matters."