Isabelita Peron, who left Argentina in chaos, eyes top post

A new poster has joined the mass of wall-to-wall propaganda in Argentina, which is revving up for October elections: ''Isabelita will return and win,'' is its simple slogan.

The woman in question is Maria Estela ''Isabelita'' Peron, the widow of Argentina's charismatic former President Juan Domingo Peron, whose legacy still strongly influences Argentine politics.

For seven years Isabelita has been out of the political picture - spending five years under military house arrest and two in exile in Spain. Under her tenure as president from 1974 to 1976, Argentina was plunged into political and financial chaos. The military coup that ended her presidency was initially widely welcomed due to her political incompetence and the corruption that surrounded her.

But she still has a hard core of supporters in the Peronist party. And as she reportedly perpares for a return to Buenos Aires, a dispute over her continuing role as party leader has split the Peronists and may be a major factor in the Oct. 30 presidential, congressional, and municipal elections.

Isabelita's strongest support comes from the traditional sector of the Peronist party, known as the ''verticalists.'' This faction believes the Peronist movement should be run along strictly hierarchical lines and that Isabelita is the only ''legitimate'' political heir of General Peron.

The verticalists, whose ideological definitions of Peronism are similar to the national socialism of Mussolini in the 1940s, are convinced that Isabelita is the only figure capable of stopping their party from being taken over by the left or destroyed by internal squabbling. They have publicly denounced the current front-runners for the Peronist presidential nomination as ''fraudulent'' since Mrs. Peron has not renounced her position as party leader.

''Isabelita has not abandoned politics, and she never will,'' says Gabriel Labake, a former Peronist congressman who is spearheading the propaganda campaign for her return.

Mrs. Peron, however, has yet to state her intentions. Many in the party say the verticalists are manipulating her for their own political ends at a time when the orthodox, strongly anticommunist faction appears to have been losing its grip on the party.

The person who has emerged, in her absence, as the strongest Peronist contender for the presidential nomination is Italo Luder, a leader of the senate , whose public image is the very antithesis of the late General Peron.

A little awkward with journalists, and a soft-spoken public speaker, Mr. Luder has opted for a moderate, middle-of-the-road manifesto, which he hopes will unite the disparate factions within the party and attract anti-Peronist voters. Backed by an elaborate and costly publicity campaign, Luder has managed to chalk up impressive victories in the local internal party elections, although the Peronist presidential candidate can only be officially endorsed by the national party convention at the beginning of next month.

''No one cares about Isabelita any more. Luder will not only win the party nomination, he's going to be the next president of Argentina as well,'' said Julio Barbaro, a close Luder aide, in the middle of a massive turnout at party headquarters last week.

Privately, however, the Luder camp is worried. The enigma surrounding Isabelita's return and the reluctance of some members of the armed forces to lift a legal ban against political activity by the former President has denied the Peronists the edge in the current election campaign.

But in April, bending under public pressure, the junta scrapped an institutional act banning Mrs. Peron from political activity and the holding of public office. The country's military rulers, however, still are debating whether to follow this up by recommending that the Supreme Court drop several court cases that charge her with embezzlement of public funds - charges that theoretically still prevent the former President from taking an active role in politics.

In the last elections, held in 1973, the Peronists won an easy victory. But recent polls have been showing Raul Alfonsin by far the most popular political figure. In recent weeks, Alfonsin has been enthusiastically endorsed by the Peronist party's traditional rivals, the Radicals, as their presidential candidate.

The verticalists believe that Isabelita should return and present herself as the only Peronist capable of beating Alfonsin. The Luder camp believes that Isabelita could put the final nail in the coffin of Peronist aspirations.

''If Isabelita does fly back from Madrid, Alfonsin will be the copilot,'' jokes Barbaro.

But neither the verticalists nor Luder's supporters are sure of their support. Often Argentine politics are primarily emotional and only secondly rational. The extent to which Isabelita can stir the hearts of the nation is still difficult to predict. Her projected return to Buenos Aires has done little to clarify Argentina's confused political scene.

While the Peronists have been caught up in their battle between Isabelita and Luder, Alfonsin has been speaking out on human rights and the role of the armed forces, presenting an image of resolution and confidence that seems to matter a great deal in this crisis-prone country.