Despite Washington's recent turmoil over nuclear arms negotiation, American campaigners for a nuclear weapons freeze have maintained a relatively low profile in recent weeks.
But some of their leaders found several matters to cheer about at a 2 1/2-day conference here last week.
The grass-roots movement, which calls for a bilateral agreement to end testing, production, and further deployment of nuclear weapons by the US and USSR, has gained added credibility with the public, according to a Louis Harris poll released at the conference.
Harris polls are not always confirmed by other national surveys. But this Harris canvass showed such a sizable majority favoring the freeze idea that it could have some influence on congressional, if not White House, policymakers.
Paradoxically, the poll also registered a sharply increased distrust of Soviet intentions. This could cut in the opposite direction with Washington policy planners.
Members of the closely knit fraternity of academic and public arms control analysts present at the Cambridge gathering also showed new respect for the activist approach of the freeze movement - a shift that could have major implications for America's arms control policies.
The conference, cosponsored by Harvard's Center for Science and International Affairs and the American Academy of Arts and Sciences, ended January 15. The same week saw the resignation of Eugene V. Rostow, director of the US Arms Control and Disarmament Agency, and the apparent intention of Secretary of State George P. Shultz to exercise a more active role in directing US-Soviet arms limitations talks under way in Geneva and Vienna. Mr. Shultz is expected to pursue a more flexible approach in the negotiations, a change applauded by many freeze proponents.
Pollster Harris told the conference that American public opinion was undergoing major changes on the nuclear freeze issue. Citing results of a poll taken in the second week of January, he said that:
* By a margin of 66 to 31 percent, the public feels President Reagan is doing an unsatisfactory job in negotiating nuclear arms reduction with the Soviets. More than half those polled (57 percent) worried that he might lead the country into a nuclear war.
* Despite the President's arguments to the contrary, a 64 percent majority thinks US nuclear strength is at least equal to that of the USSR, up from 53 percent in 1980.
* The Soviets are viewed as hostile to the US by an 85 to 9 percent majority - up from a 69 to 21 percent split in 1976. Now, 51 percent see the USSR as an outright enemy of the US, the highest recorded percentage, said Mr. Harris, since the cold war days of the 1950's. And 69 percent feel the Soviets would not hesitate to use nuclear arms if attacked.
* Yet, by a 76 to 21 percent split, some three-quarters of those polled favored negotiating an agreement with the Soviets on a nuclear freeze - although 82 percent oppose unilateral disarmament.
Freeze proponents, who have gathered more than 2 million signatures on petitions in the past year and who are gearing up for a vote on the issue in the US House of Representatives in early March, were clearly pleased by the poll.
Harvard Law School professor Abram Chayes noted that participants in the conference (which included representatives of the administration and of all but the most hawkish wings of the arms control community) agreed that ''the political impact of the freeze movement has been very high.''
And Dorothy Zinberg of Harvard's Kennedy School of Government noted that the trend in the past year has been to take the discussion of nuclear arms control out of the hands of the ''nuclear theologians'' and put it into the hands of the public.
Those ''nuclear theologians'' - specialists in arms control - have traditionally been suspicious of activists in the freeze campaign, and have tended to give short shrift to the latter's proposals. Jeremy J. Stone, director of the Federation of American Scientists, quipped that, among arms controllers, ''raised eyebrows have substituted for analysis [of nuclear freeze proposals] for a long time.'' He noted more seriously that ''we've suffered in the last 20 years by trying to do arms control without popular support.
Now, says Randall Forsberg, widely credited as the founder of the freeze movement, there is at last ''the beginning of a discussion between the arms control community and the activists.''