WASHINGTON — George Bush's road to the White House in 1988 was paved by the spectacular political success of Ronald Reagan. Not only did Reagan win two presidential elections in landslide style, but his conservative thrust transformed the debate over public policy.

Yet no sooner did Bush take over the Oval Office than he began making adjustments in the steady rightward course Reagan had steered. Mostly symbolic at first, Bush's changes have become more substantive as he moves into the second half of his term--and closer to the 1992 election.

On issues from energy and education to day care and defense, where Reagan was dogmatically conservative, Bush has moved toward more moderate positions, striving to blunt the attacks of liberal critics and--more important--to meet the needs and demands of the electorate.

Responding to criticism that the nation was overly dependent on foreign oil, Bush offered a plan to boost domestic production by 3.8 million barrels a day over the next 20 years. On the environment, he broke a legislative logjam that had dragged through the entire Reagan presidency and signed on to a historic revision of the Clean Air Act. He proposed a day-care program that would help provide more than $20 billion in aid to lower- and middle-income families. His education program, outlined last month, proposes a combination of national testing and standards and model schools to promote "a new renaissance in American education."

And on defense, where Reagan stubbornly sought to keep his massive buildup alive, Bush has bowed to economic realities--and the sudden ending of the Cold War--and is actively working to design a scaled-down but still effective military.

It is too soon to tell whether Bush's tactics will result in an advance or retreat for his party from the political gains Reagan made. Indeed, some analysts contend that despite his Operation Desert Storm triumph, the severest tests of Bush's political leadership still lie ahead.

But what is beyond dispute is how well Bush has managed up to now to match his performance to the mood of the country during the transition to the post-Reagan era.

"More reactive than proactive in terms of a policy agenda," wrote University of Pittsburgh presidential scholar Bert Rockman, "Bush came into office perfectly congruent with the historical and political moment."