THE President is widely perceived as having been less than decisive in Beirut and less than open and aboveboard in dealing with Nicaragua. Indeed, there is a widespread feeling that Ronald Reagan does not have clearly defined foreign policy. The President is being faulted for the budget deficit and an economy that many say won't hold up. And yet. . . .
At the same time every Democratic presidential candidate and every Democratic leader is openly conceding that the President is formidable politically and that Mr. Reagan may well be unbeatable.
His persistent amiability is unsettling for his foes. Reagan's most outspoken critics find themselves conversing in a most friendly way with him when he asks them to drop by the White House.
One clue to Reagan's ability to ride serenely above the storm comes from Barry Sussman, who analyzes Washington Post/ABC News polls. ''By many of the standards that opinion analysts use,'' writes Sussman, ''Americans are far more optimistic about themselves and President Reagan at the end of 1983 than they were when the year began.''
When asked whether Americans ''feel they are better off than they were three years ago,'' economist Walter Heller - a friend and adviser of Walter Mondale - said: ''They feel they are better off. And they are better off.''
The disadvantaged and the poor don't feel that way. But these are people who didn't vote for Reagan. They make up about 35 percent of the public which, Sussman points out, have never been a part of the adorers-of-Reagan group.
But there is something else in the President's strong political position beyond this better feeling that people have about themselves. It is this: Mr. Reagan, whether one likes what he has been doing or not, has shown that he has a knack of getting what he wants done or blocking things he doesn't want done.
James MacGregor Burns - whose ties are with the Democrats - has said that Reagan had shown a remarkable ability to make a well-nigh unworkable US government process work. Of course, Dr. Burns would like a less cumbersome government system. And these days he is pushing for one that would more likely guarantee that a president would have a Congress more responsive to the direction he would like to carry the country.
Having made it clear he didn't agree with Reagan on anything he was doing, Dr. Burns did make this concession: Reagan had shown much skill in pulling a coalition together to move his program along.
A longtime liberal who heard these comments grudgingly made this concession about Reagan: ''I guess you have to say the President has shown leadership.''
Reagan's many admirers see a leader in the President. So do his critics. The latter are well aware that the President retains this ability to keep the people behind him. Thus, they are anxious about his strength, not his weakness. They are concerned about this retained Reagan presidential clout and where he might be able to take the country, in both foreign and domestic affairs.
From friend and foe comes the perception that Mr. Reagan is in charge. Little wonder that the suspicion has occurred to many Washington observers that some of the Democratic candidates really had their eye on 1988, not 1984 - when Reagan would no longer be on the scene.