Reagan's back in the saddle again. President returns to ride herd on issues that could cause him trouble

President Reagan is back in the White House. But as he gradually resumes work, buoyed by an outpouring of popular support following surgery, he faces an array of problems that could take some gloss off his presidency. Six months into his second term, political analysts see these issues potentially causing trouble for Mr. Reagan:

Now that the President has ruled out higher taxes, social security decreases, or further cuts in defense spending, Congress is agonizing over how to hammer out a budget resolution for fiscal 1986. Even if it succeeds, the budget will not significantly curb the soaring deficits, which may continue in the area of $200 billion a year because of a slowing economy.

Reagan's tax-reform plan has not developed the hoped-for momentum. Many Americans voice concern that the package favors the rich over the middle class -- a perception forcing the administration to revamp some provisions.

As the United States trade deficit grows to alarming size, the administration is resisting protectionist trade moves in Congress. But polls show that the public favors stronger action against Japan and other countries whose goods are flooding the US and adding to the trade deficit.

The President's popularity continued to remain high even before surgery, and his courage and grace under physical stress will likely give his approval ratings an added lift. But this is not expected to translate into political influence on Capitol Hill. His problems on the home front suggest that Reagan increasingly has to grapple with the political realities of a lame-duck second term.

Some see this problem as largely institutional, an impasse between the executive and legislative branches traceable to the fact that by law the President cannot run again, while lawmakers must face voters in 1986 and '88.

This is a fact of life for every second-term president, even one reelected by such a huge majority of voters.

``The presidency is challenged by a natural life cycle and we are in a cycle of decline,'' says Paul C. Light of the National Academy of Public Administration. ``Things are generally in stalemate and likely to remain that way as we move to the '86 and '88 campaigns.''

Many lawmakers agree. ``Institutionally we are becoming less able to respond to the crises that are facing us,'' says Rep. Leon E. Panetta (D) of California.

Other analysts suggest that the Reagan forces overstated the amount of public support for radical changes in federal spending. Most Americans, they say, want to curb uncontrolled spending but do not want to give up government benefits. Lawmakers, therefore, are responding to the public mood. As Lester M. Salamon of the Urban Institute puts it, ``Reagan's tried to go beyond his mandate, and Congress is marching to a different drummer.''

The President apparently felt the political heat after he went along with Senate Republicans on a temporary freeze on social security cost-of-living increases. That would account for his recent reversal on the issue. In any case, the senators are still smarting from being left out on a limb by Reagan's reversal, and this could affect their support for other Reagan programs, including tax reform.

This does not mean the ``Reagan revolution'' is over. Basically passive about the budget deficit, the President is more concerned about further cuts in domestic spending. And the Senate now is pressing House lawmakers to make deep reductions in programs.

So the dramatic course that Reagan launched during his first term is not being reversed. ``While a lame-duck president loses power to effect [change], he retains a veto on change by the Congress,'' says Stephen Wayne, a presidential scholar at George Washington University. ``He can prevent Congress from undoing his deeds.''

In some respects, Reagan has done reasonably well in his second-term relations with Congress. Forced to compromise on many issues, he has made compromise appear more like a victory than adevastating loss. Reagan finally extracted congressional approval for US nonmilitary aid to the Nicaraguan rebels. He won a number of votes on the controversial MX missile.

House Democrats, not wishing to be tagged as soft on defense and communism, have supported other items on the conservative Reagan foreign policy and defense agendas: increased aid for pro-US foreign insurgents, repeal of a ban on US aid to antigovernment rebels in Angola, more defense spending, and a nerve-gas weapon system.

``In tactical terms he's making the Congress uncomfortable on several issues,'' says David Newsom, director of Georgetown University's Institute for the Study of Diplomacy.

On the diplomatic front the President has yet to achieve progress in such crucial areas as arms control and the Middle East. Yet, despite strong rhetoric against terrorism and communism, the President is pursuing a cautious foreign policy that seems to suit the national mood. Americans want the US to look strong in the world, but, tired of world crises, they also favor keeping American involvement abroad to a minimum.

``Americans want the thrill of `Rambo' movies and belief in US global resurgence -- in short, an imitation of the successful Eisenhower era instead of the hand-wringing Carter years,'' writes conservative analyst Kevin Phillips in a recent newsletter. ``But at the same time, they know that the US can no longer back up this image with Eisenhower-era reality, so they're just as happy with a president who doesn't implement too much of his rhetoric.''

What will largely determine Reagan's political fortunes, however, is the state of the economy, say many observers. If the country were to plunge into another recession, the President's support might correspondingly decline, as it did during the first-term economic downturn.

But for the moment, even Democrats do not cease to be amazed at Reagan's ability to capture the public mood and embody Americans' yearnings for self-confident leadership and a sense of well-being.

``We live by symbols and often the symbol is more important than the substance,'' Rep. William H. Gray III (D) of Pennyslvania, House Budget Committee chairman, told reporters recently.

``Particularly in an industrialized society that tends to depersonalize, the symbol becomes even more important than reality. This President is a master of symbols.''