Bush's Tone Set; Now for Direction. CONGRESS WATCHES

THREE weeks into the Bush presidency Washington is still asking: Where is George Bush headed? What are his plans and priorities? Political observers say that in these early days of his administration President Bush has managed to set a different tone and style - one of openness, personal energy, and ethical concern. But it remains unclear in what direction he hopes to take the country and how he intends to get there.

Tonight that perception may change. Mr. Bush will give a speech to Congress setting forth his budget program and his domestic and foreign policy agenda. It could set the standards against which his presidency will be measured over the next four years.

``If he has serious priorities - environment, drugs, ethics - now is the time to unveil and emphasize [them],'' says William Schneider, a political analyst at the American Enterprise Institute. ``He can define them now and hit the ground running instead of coasting.''

So far, analysts say, Bush has left the Reagan agenda largely intact, despite some marginal adjustments in areas like ``star wars,'' or the Strategic Defense Initiative, and aid for the contras. This is not surprising, they say, given that Americans in effect voted for continuity, not change.

Bush has in fact two principal objectives - to keep the economy moving and to keep the new d'etente with the Soviets on track. Most of his public pronouncements have dealt more with themes than specific proposals (although this week he unveiled a plan to bail out the savings and loan industry).

Instead the President has focused on changing the atmosphere of government - and his image of the ``tough guy'' conveyed during the campaign to a Washington insider and professional. His frequent meetings with lawmakers, both at the White House and on Capitol Hill; his reaching out to minority groups and environmentalists; his accessibility to the news media; his lecturing of government employees on ethical standards - even First Lady Barbara Bush's visits to the poor - have sought to establish a tone of bipartisanship, integrity, and social concern.

``He has enjoyed success manipulating the symbols and values without defining his agenda,'' Schneider says.

Whether the public expects dramatic innovation from Bush is open to question. Experts say there is no pressure for or expectation of radical change. At the same time Americans give Bush a rather measured assessment.

After a week in office, a Gallup survey found that 51 percent of Americans said they approved of how Bush was handling his presidential duties, about the same as Reagan received in the same period. But Bush had a lower disapproval rating than Reagan (6 percent for Bush vs. 13 percent for Reagan) and, significantly, received the largest ``don't know'' response ever.

``People don't know what to make of him,'' says Andrew Kohut, president of the Gallup Organization. ``He's not a well-defined man.''

By contrast, other first-term presidents received far higher ratings early in their term: Carter (66 percent), Nixon (59), Kennedy (72), and Eisenhower (68). Bush's approval and disapproval ratings will rise, Gallup says, as the public gets to know him.

But in contrast to the public's early views of Reagan, the Gallup poll also found that equal proportions of blacks (51 percent) and whites (52 percent) approve of Bush's handling of his job. ``This has never happened before, so blacks are giving Bush the benefit of the doubt,'' Mr. Kohut says. ``Bush has made some hay with blacks, who did not like Reagan.''

To some extent the traditional ``honeymoon'' that Bush has been enjoying has frayed. For all of the President's rhetoric about rectitude in government, for example, several of his appointees, including Secretary of Defense-designate John Tower and White House counsel C.Boyden Gray, have found themselves targets of criticism on ethical issues.

But political observers see no serious signs of disarray. In the main, Bush is viewed as having adopted a strategy of setting a mood and tone and of continuing the policies of recent years with incremental changes here and there. Given budget constraint, analysts say, Bush does not want to set himself up for dramatic moves that could encounter early defeat, so he is cautious in his dealings with Congress.

``It's an explicit strategy based on the view that the economy is doing reasonably well and that the basic course is OK,'' says Thomas Mann of the Brookings Institution. ``The strategy is one more of style than substance, adjustment rather than reversal, and of a `new breeze' rather than a clean broom.''