AFTER LENDING Ronald Reagan's presidency an unusually long immunity from criticism, the media has recently begun to strip its coverage of the varnish that had shielded the President for more than a year. His sputtering economic policies, increasingly apparent insensitivity on civil rights, and vacillating foreign policy-largely shot from the hip-have even made Reagan's admirers begin to reel in disbelief and exasperation. That the press had treated the President with kid gloves, while fully aware of the White House's blunders incoherence, and incompetence now seems a particularly irresponsible error. But at least journalists are finally hungering to expose the President's inability to deal with the nation's very real problems. It's only unfortunate that that eagerness came months after public reaction swung against Reaganism.

Ironically, former President Carter's campaign strategy of attacking Reagan as too dumb and too dangerous to sit in the Oval Office is being borne out by the President's vacuous statements, his staff's clumsy coverup of gaffes, and the increasing alarm of his Republican "allies." Previously hailed as the Great Communicator, exuding amicability, confidence, and resourceful leadership. Reagan has emerged as a narrow-minded simpleton, impervious to practicable political bargaining and constructive suggestions. And the press is now hammering that point home.

The watershed that signalled the press's turn-around seems to have been an article last month by New York Times columnist Anthony Lewis '48. Discussing how Washington reporters had insisted on giving the President an easy ride in spite of his errors. Lewis argued that the press has almost deliberately covered up Reagan's gaffes. Lewis implicitly called upon other members of the Fourth Estate to stop cushioning Reagan and to start playing up his ineptitude.

LEWIS ARGUED that the ginger treatment of Reagan stemmed from three factors. First, Reagan's 1980 landslide and his dexterity in forging what appeared to be a political consensus earned him political respect and legitimacy. His success in winning Congressional tax and budget battles sheltered his weaknesses from immediate exposure. Second, Lewis contended, some journalists are gun-shy because they worry their views on issues are more liberal than the President's and that the public would thus not take hard-hitting accounts seriously. Both those reasons for journalistic quiescence become irrelevant, however, when their raison d'etre-public and Congressional backing of the President-fades. Reagan's waning influence, accelerated by the Administration's internal backbiting, undermines any argument for laissez-faire press coverage.

Republican Senate veterans like Robert Packwood (R-Ore.)deserting Reagan's cause. As the Administration's cuts in social services hit home, the political mood of the nation has shifted further from the right, Sensing this, the press will be less fearful of tempering what once could have been deemed "subjective liberal" criticism.

Lewis's third reason for the overly protective reporting is not reason at all; it is a subtly satiric prodding of his fellow journalists' failure to evaluate Reagan's competence. Some reporters and editors have clammed up, he contends, precisely because they are so frightened by what they see in the President.

"They see a man who acts without real information. They see a man with an anecdotal view of the world, who may apply in EI Salvador lessons of imagined history in Vietnam. They see a man who gives simplistic answers to complicated questions. They care about their country, and they find it too upsetting to acknowledge-to the public or to themselves-that the enormous power of its leadership is in such hands."

Perhaps. But they too longed to give Reagan a chance to put his program into action, in the vague hope that America would be better off than it was a year ago. But, as any poll will suggest, his palliatives are failing. The nation over which Reagan presides-not leads-is in a gloomy mood. The press is reacting to this public crisis of confidence as the President's recent, ragged, now-adversarial press conferences show.

THE MEDIA, then, seem finally to be monitoring the national heartbeat, albeit a few months after the nation's anxiety began to escalate. The deepening recession and the President's inability to articulate a thoughtful, coherent economic policy is forcing the President, who refuses to bend of compromise, into a corner of isolation. As the White House's promises become mere verbiage. Reagan's Medical changes seem little more than a wishful ploy with evanescent political usefulness.

When Reagan was riding high in the saddle, his resolve and steadfast determination elicited praise and lent him an image as a commited and unwaivering leadership-s President who did what he laid. Now Reagan's initiatives appear carelessly and irresponsibly constructed. The dissension among his staff and Republican leaders now make Reagan seem a simpleton, typecast and mean-spirited. During Reagan's honey moon with both press and Congress he could afford rigid and dogmatic complacency. The press's belated but welcome scrutiny can only help make him reconsider-or stick to his guns and face political stalemate or disaster.