TRAVERSE CITY, MICH., JULY 28 -- The National Governors' Association closed its summer meeting here today with incoming chairman John H. Sununu (R), governor of New Hampshire, calling on the group to focus on ways to undo what he called the "drastic overcentralization of power in Washington."

Sununu asked fellow governors to make suggestions on how federal rules and regulations could be changed to restore power to the states. And he said he will set up an association task force to explore proposals ranging from umbrella federal legislation to a constitutional amendment that would permit a two-thirds majority of states to nullify federal laws they believe infringe on their sovereignty.

Although many of the governors here said they share Sununu's frustration over the erosion of state authority at the hands of the courts and Congress, there appeared to be only modest interest in a constitutional amendment.

"I'm not sure we could get a consensus on that," said Indiana Gov. Robert D. Orr (R), noting that association bylaws require adoption of policy proposals by a two-thirds vote.

Both Sununu and Virginia Gov. Gerald L. Baliles (D), the incoming vice chairman, stressed that the focus on state rights should not be seen as an effort to revisit the civil-rights issues that have been at the core of past states-rights movements.

Protection of individual rights are understood by the states to be the domain of the federal government, they said. Rather, they said, they want the states to be able to assert more control over managing programs ranging from transportation to health care to education to welfare -- all areas where governors say they feel constrained by federal laws.

In other business, the governors adopted a statement on AIDS that emphasized education over testing as the most effective preventive measure. And they called for an unspecified increase in federal spending on education and research.

The policy, drafted by Rhode Island Gov. Edward DiPrete (R) and Massachusetts Gov. Michael S. Dukakis (D), called for education programs for the general population, including schoolchildren, as well as for high-risk groups, such as male homosexuals and intravenous drug abusers.

Ohio Gov. Richard F. Celeste (D) said there was an "omission" in the association's failure to address the "urgent and often controversial subject" of testing, but Sununu said the subject would come up again, as more information about the nature of the disease becomes available.

The association heard task force reports on how governors are dealing with welfare, teen-age pregnancy, illiteracy, alcohol and drug abuse, and school dropouts. The approaches were all built around what outgoing Chairman Bill Clinton, governor of Arkansas, called a "social contract in which no right can be asserted without citizens taking on a corresponding responsibility."

Clinton, striking the pragmatic, middle-of-the-road tone that most governors of both parties find comfortable, said that government can be "neither a spectator nor a bystander" in the effort to attack pressing social problems.