Unbeknownst to Sen. Edward Kennedy but symbolic of his burdened presidential candacy, the United States had virtually completed arrangements for the shah of Iran to go to Argentina when Kennedy's blast at the toppled shah as one of history's worst tyrants killed the deal.

The collapse of the secrets U.S.-Argentina negotiations, following the earlier, sudden switch of Mexico in turning back the shah, may be the only damage done President Carter and his Iran policy by the senator's harsh assault on the shah. But for Kennedy himself, self-inflicted damage from the calculated effort to promote his unnoticed presidential campaign back onto page one will not be so limited. Indeed, in portraying Ted Kennedy in yet another stumblebum guise, it is potentially disastrous.

The calculation is indisputable. The formulation of Kennedy's attack on the shah "had been thought out carfully," Tom Southwick, his press secretary, told us. Traveling across the country to campaign in California last weekend, Kennedy and five top aides worried about the lack of page one play despite the large traveling press contingent that accompanied him.

The reason: the only story in the world is Iran and the American hostages; the only beneficiary of that story is Jimmy Carter, whose job Kennedy covets.

Kennedy had heard criticism from Hispanics in Los Angeles about unfair immigration procedures for Mexican immigrants and their families. The next morning he reads in The Los Angeles Times a suggestion from Ronald Reagan that the shah be given political asylum in the United States. Having carefully ducked any critical comment on Iran for the past month, Kennedy grabbed the Hispanic complaint and made it a bridge for his attack on the shah.

Hours after the attack, which couched in characteristic Kennedy hyperbole, neither the senator nor his aides realized that he had committed a major campaign blooper. This failure to grasp reality is a mark of the amateur. I can be corrected, simply enough, by the addition of a senior staff man familiar with the special day-to-day problems that abound in any presidential campaign.

Yet finding a senior staff man skilled in practical politics has not been given high priority in Kennedy's campaign. Instead, the staff bulges with ideological experts untutored in the arts of politics but deep in pursuit of relatively obscure objectives in foreign policy unlikely to win votes. For example, Mark Schneider, a key State Department architect of the Carter administration's much-criticized human rights policies, resigned his job last month to join Kennedy's staff as an "issues" adviser.

Amateurism is one deficiency that was not expected in Kennedy's presidential campaign by most politicians. The expectation that Ted Kennedy would show the same professionalism of his brothers John and Robert suffered its first setback in his CBS television interview with Roger Mudd. There have been additional setbacks since then.

But the failure of Kennedy and his entourage to comprehend the damage of his attack on the shah is by far the most dangerous setback. Some politicians now are asking each other: is it possible that Ted Kennedy really is a stumble-bum?

A still deeper problem for Kennedy lies beyond this lack of professionalism: the problem of his depth of ideological conviction. Sen. Henry Jackson, a centrist, defense-oriented Democrat, has privately told party leaders of similar persuasion -- particularly labor leaders -- that, like John F. Kennedy, Ted Kennedy is pragmatic and political, not ruled by ideology.

Wanting to find out, J.C. Turner, president of the operating engineers' union, was promised after a private chat in Kennedy's office Nov. 5 that the senator would send him speeches and statements showing an acceptable record on defense issues. Turner is still waiting for them.

To the many Democrats like Turner who worry that Kennedy's ideological commitments may in fact be deep and abiding, and not merely political, the assault on the shah has ominous overtones. It smacked of real conviction that, in Kennedy's mind, the shah is indeed one of history's monsters. For the senator, that could prove even more costly than the curable problems of political amateurism.