Many Capitol Hill lawmakers have been quick to impugn David Stockman's credibility. But it might be argued that the budget director's credibility has in fact been enhanced. His candid confessions to an Atlantic Monthly reporter were an indiscretion and have embarrassingly damaged the image of the President's economic recovery program. But in a certain sense the magazine article clears the air of some economic silliness.
Mr. Stockman said or implied what many economists believe: that ''supply-side'' economics is a euphemism for ''trickle-down'' economics; that the political power of rich special-interest groups saved them from the ax which fell on unorganized ''weak clients''; that the projections of high economic growth and low budget deficits were too optimistic; that the only way to balance the budget given a huge loss of tax revenue is to tackle such areas as defense spending and tax loopholes and/or impose new taxes. Wall Street, of course, sensed the flaws and reacted ac-cordingly.
This does not mean the administration's basic program should not proceed, with whatever adjustments are needed to make it work. Now that a good dose of honesty has been injected, the question is: will the Congress and the White House do what is necessary to bring the budget under control as President Reagan has vowed to do? The deficit for fiscal 1982 is now estimated at $100 billion, the largest in history. Its importance should not be exaggerated. It represents a smaller proportion of the gross national product than have past deficits. Note , too, that interest rates are beginning to come down even while the deficit is growing. Recession accounts for that - showing that federal fiscal policy does not have as overriding an influence as some claim.
But it does have some impact and, more important, the principle that government should operate within its means is a sound one to be pursued. The deficit should be reduced. Defense, for example, was spared the President's deep cuts for foreign policy (and domestic political) reasons. But, as the Stockman analysis bore out, this is a fertile area for savings - $10 billion, $ 20 billion, $30 billion a year, perhaps.
Indeed Congress has good reason to take a close look at two weapons systems whose value is dubious. The costly MX missile program, for one, appears to be unnecessary. Because the MX missiles would be in fixed silos, rather than mobile , they would not close that ''window of vulnerability'' which gave rise to the scheme in the first place. The MX would merely provide the US with a first-strike counterforce capability likely to lead to a race in antiballistic missile defense systems, which now are under treaty control.
Then there is the B-1 bomber. It presumably would be in service two or three years before the more advanced Stealth plane and in this brief period would be effective against Moscow's early-warning system. But is that worth the enormous cost? Especially when the B-52s are to be armed with cruise missiles and do not need to penetrate Soviet air space? As Sen. Ernest Hollings, no dove on defense , argues, the B-1 would be splendid if the US could afford everything. But, with only marginal benefits expected, it might be better to wait for the Stealth. The only risk would be if the Pentagon failed to ride herd on the Stealth developers to meet their deadlines.
Other areas, too, offer revenue opportunity. Tax ''expenditures'' loom large - the budget term for deductions, credits, and exemptions which favor a whole array of special interests. Congress will necessarily have to tread carefully at a time of recession but, eventually, elimination of many of these tax loopholes - such as deductions on second-home mortgages and certain consumer-credit interest, tobacco and sugar subsidies, over-generous veterans' benefits - would provide billions of dollars for the Treasury.
We would also have the Congress look at lifting controls on natural gas prices and imposing a windfall profits tax to sop up the excess profits of producers already making high earnings. Here again, recession dictates caution. One would not wish to impose hardship on people by causing higher fuel prices in the immediate winter months. But stepping up the timetable for gas deregulation would make sense. Consumers of natural gas continue to pay artificially low prices for the product. Removing controls would boost exploitation of the nation's vast gas deposits, encourage conservation, and further reduce oil imports, thus contributing to national energy sufficiency. The public, jarred for a while, would nonetheless adjust to new natural gas prices just as it has in the case of oil. And the government would have a prolific new source of revenue.
The US government, in short, need not succumb to ''deficit blues.'' There are plenty of ways to fill the gaps. A tighter defense budget, a courageous assault on tax favoritism, a still more rational energy policy - these would not only fill the government coffers but make possible continuation of those federal services and programs which are worthwhile and essential. Mr. Stockman let the cats out of the bag. But his aired disappointments and doubts point the way to better policies.
Will the lesson be heeded?