The Reagan administration hopes last Sunday's election here will shore up waning international and domestic support for United States policy in El Salvador.
As the ballots are being counted, President Reagan is pointing to the election to justify his request for increased military aid for the Salvadorean Army. He says the vote demonstrates that El Salvador is building popular democratic institutions.
At the same time, the US Embassy here has been busy over the past week accommodating visiting election observers - US congressmen, European and other foreign dignitaries, and some 700 foreign correspondents - many of whom are on their first trips to El Salvador.
US officials see the election as an opportunity to impart their understanding of the conflict here and to present their proposed solutions to the conflict to an audience that has neither the time nor the resources to investigate the situation independently.
The US's financial investment in the Salvadorean presidential campaign has run to more than $10 million. The political investment, however, is far greater.
If the moderate-left Christian Democratic candidate Jose Napoleon Duarte emerges as president in a runoff vote, expected to be held in about 30 days, US influence in El Salvador could increase. But if right-wing presidential candidate Roberto d'Aubuisson wins, the US role here could fade quickly.
Although President Reagan says El Salvador is building democratic institutions, most on-the-scene observers agree that it takes a great deal of imagination to turn the Salvadorean political landscape into anything resembling a democracy. There is no independent judicial system. The legislative and executive branches of government have authority on paper, but little in actuality. The military continues to dominate government and alleged leaders of death squads not only go unpun-ished, but also retain high government posts.
On election day, Western views and expectations of the presidential elections clashed markedly with those of the poor peasants who make up most of El Salvador's population. As network cameras recorded the voting and international delegates fumbled with the few words of Spanish they knew to communicate with those waiting to cast ballots, many, if not most, Salvadoreans dreaded the moment they would be handed the thick black crayon to mark an ''X'' on their ballot.
Gripping a crayon and writing an ''X'' is an awkward and difficult task for illiterate peasants. As they struggle to hold pencils, and then mark their ballots, their estrangement from 20th-century culture became embarrassingly evident.
In return for hours of waiting in line under a blistering sun, the peasants who voted received a blue stamp on their state ID cards. (Voting is compulsory for adult Salvadoreans.) The stamp was being checked by soldiers even before the balloting ended Sunday.
What the US and Salvadorean governments hope to gain from the elections, however, is less clear.
The logistical failures of the election have tainted the credibility of the electoral process. One political party, Democratic Action, has already called for an annulment of the vote. The National Concil-iation Party has petitioned the Central Electoral Commission to invalidate the votes in 1,167 ballot boxes from around the country, alleging voting irregularities.
The first official preliminary vote counts were issued Tuesday afternoon. These figures were retracted by the Central Electoral Commission and new figures substituted three hours later. These figures, drawn from a few towns in San Vicente Province, have done little to satisfy the demands by political leaders here for an explanation of why the commission is having so much trouble conducting the vote.
A vote count early Tuesday morning, reflecting votes cast in six of the 14 provinces, showed that Christian Democrat Duarte and d'Aubuisson of the rightist party are neck and neck in the Sunday vote. But a complete vote count is expected Friday. A runoff vote is expected within 30 days because none of the candidates received 50 percent of votes cast.
The Reagan administration must face the possibility that National Republican Alliance leader d'Aubuisson could be elected president. Most observers here think the March 25 vote will show d'Aubuisson in second place behind Duarte.
D'Aubuisson's open disdain for the Reagan administration's objectives in El Salvador could make him a major liability for Reagan policy here. D'Aubuisson is alleged to have close ties to the death squads. His political ideology appears to hold democratic institutions and human rights in contempt. So a disenchanted Congress could potentially curtail, or even cut off, US aid to El Salvador if d'Aubuisson is elected.
The election of Christian Democrat Duarte, on the other hand, could result in increased US involvement in El Salvador. Duarte, an advocate of moderate social reform, would be a more acceptable leader to a skeptical US Congress.
Duarte, who was physically abused by state security forces in 1972, has little sympathy for the brutal tactics employed by the military here. At the same time, he has such small following within the armed forces that his political power, upon taking office, probably would be marginal.
Some Reaganites view Duarte with suspicion, according to an embassy official here. His political populism is not in tune with the political agenda of the Reagan administration. But he is preferred over d'Aubuisson.
Most Reagan backers seem to have favored the candidate who appears to be coming in third, National Conciliation Party candidate Francisco Jose Guerrero. Guerrero is viewed malleable and lacking a political ideology, thus he would not be expected to buck US policy decisions.
Many expect d'Aubuisson to try to resurrect the right-wing coalition that elected him president of the Constitutent Assembly after the 1982 vote.
In that year, the Christian Democrats came out ahead, but lost control of the assembly because the Nationalist Republican Alliance and four other right-wing groups together elected d'Aubuisson. This strategy could be used to defeat Duarte in the final round.
But the wild card may be Guerrero's National Conciliation Party. The PCN provided much of the support needed to elect d'Aubuisson in 1982, but this time many expect party members to split their votes between Duarte and d'Aubuisson in the runoff.
The Christian Democrats are known to have approached Guerrero, seeking his support.
But even if Guerrero backs Duarte, there is no certainty that PCN members would follow his lead. It is gend'Aubuisson; and one, Democratic Action, supports Duarte.
The five small parties appear to have garnered no more than 7 percent of the vote altogether. But in a close contest, their votes could provide the margin of victory.
PROJECTED RESULTS OF EL SALVADOR ELECTION Eligible voters 1.6 million Votes cast 1.1 million Vote tally as projected by the Christian Democrats based on 90% of ballots counted DUARTE 45% D'AUBUISSON 29.4% GUERRERO 18.6% 5 OTHERS 7%
However, El Salvador's Central Electoral Commission reports Duarte and d'Aubuisson are neck and neck, based on a vote count in 6 of 14 provinces.