Let the American public not be swept up by a growing chorus of voices proclaiming a failed presidency. The last thing the nation needs is a feeding of anxiety about the stability of government. Yet there is risk of that, with the influential New York Times speaking of the ''stench of failure'' hanging over the White House, respected political analyst David Broder talking of President Reagan's ''phaseout,'' and television vividly reporting the disarray in domestic and foreign policies.
Perhaps a bit of calm and perspective are in order.
It would be naive not to recognize the political and economic difficulties in which Ronald Reagan finds himself. It might be helpful to point out, however, that American presidents at midterm often confront a crisis of leadership, a letdown of public expectations, and an almost feverish rush of critics to attack the chief executive once it appears he is in trouble. Harry Truman had immense problems at the halfway point. So did Jimmy Carter. Some leaders emerge in better shape than others, but the phenomenon of midterm doldrums is not uncommon.
Mr. Reagan's problems are extremely severe. Indeed the nation is again reminded that, however determined, sincere, and able a politician, it is one thing to win presidential office and quite another to govern. In terms of his promises - a revitalized economy, a balanced budget, a strengthened foreign policy, a reduced federal government - Mr. Reagan has not delivered. There are some extenuating circumstances for this, to be sure, and it would be unrealistic to think that these major goals could have been fully achieved in a short two years. But the President cannot escape responsibility for the flaws of Reaganomics and the confusion in diplomacy. Nor can he escape the loss of confidence among many Americans because of the perception that he is insensitive to civil rights, racial progress, environmental issues - and in general to the down and out. Polls showing that Mr. Reagan would trail two Democrats if elections were held today are an indication, if perhaps a temporary one, of the present mood.
No one knows better than Mr. Reagan that there will always be a rush to fill a power vacuum created by weakened leadership. The Democrats in Congress will no longer be so pliant. And the Republicans, too, are beginning to distance themselves from the White House and to act with greater independence. Howard Baker's decision not to run for the Senate again is a sign of the rising temperature among GOP presidential hopefuls.
But Mr. Reagan is too experienced a leader not to resist the gathering storm of opposition. He knows that ''failure'' can be averted through compromise, flexibility, and a sense of political realism. The question is whether he will display enough of it, and in good time, to turn the tables on his critics - and provide the country with the intelligent, effective leadership it still requires.
Mr. Reagan needs to think through his policies and ask some basic questions. Have his aides given him the best advice on the economy, the budget, the nuclear balance, defense? Has he listened to the right people? Is he perhaps hanging on to biased preconceptions or misconceptions about the world, and too obstinate to change? Above all, is he engaged enough in the process of governing? Without wishing the President to become burdened with detail, as was Jimmy Carter, there nonetheless seems to be a lack of involvement. Mr. Broder refers to Mr. Reagan's extraordinary ''detachment'' in the light of current problems. Certainly his relaxed style of management should not rule out sharpened personal attention to issues, which are more complex than Mr. Reagan's pronouncements seem to suggest.
If the presidency looks in some disorder now, it could look much better in two years' time. Mr. Reagan's popular support has not dropped disastrously, and with the needed corrections to his policies, in line with what the American public supports, he could rebound. By rationalizing military spending, reducing the projected federal budget deficits, getting out front on the reform of social security, and, not least of all, accomplishing something abroad - negotiating an arms control treaty and launching Arab-Israeli peace talks - Ronald Reagan could still put his own stamp on the US presidency.
It will be harder now because he is politically weaker and will have to contend - and compromise - with other centers of power. But that will be the test of his leadership. Surely the American people want him to meet that test.