Altagracia Lopez, a maid, left the capital to the politicians today, preferring to spend Sunday's election in the safety of her parents' provincial home. She is among thousands of people who can hardly believe that for the first time in the history of the Dominican Republic a transfer of power may occur without either U.S. or domestic military intervention.

"I'll be back on Monday," she told her employer, "if it's all over by then."

A Yankee hand in any shift is so basic an assumption here that the State Department's reiteration of neutrality made headlines in all eight feisty local newspapers last week. A similiar declaration by the Dominican armed forces chief of staff, also front page news, "made us all relax a little," said a prominent attorney.

Since Christopher Columbus landed here in 1492, power transfers generally have been by force, and Dominicans have grown cynical dodging the crossfire. But as nearly 2 million voters prepare to go to the polls, U.S. policy in the Caribbean and Central America stands to pass an important milestone that could make this island nation the Reagan administration's model for other countries in the region.

If all goes as expected on Sunday, there could be a peaceful election, watched by a free press, that results in major rebuffs but not repression, for both the far right and the far left. And from Washington's viewpoint, the climate for U.S. business will never have been better.

The leading presidential candidate, attorney Salvador Jorge Blanco, is counting on increased U.S. aid and trade to keep the economy afloat. At 54, he is the articulate, energetic chief of a reformist Dominican Revolutionary Party (PRD by its Spanish initials) that believes state action can defuse the political extremism that feeds on poverty.

"For our generation," Jorge Blanco said in an interview, "an economic crisis is an opportunity to resolve problems." He will have ample opportunities. Unemployment is 30 percent in the cities, according to State Department figures, and higher in rural areas where the rolling fields of green sugar cane can no longer produce enough export income to import food for the 5.5 million Dominicans.

With five parties in serious contention, Jorge Blanco and his Revolutionary Party are ahead by 20 percent or more in four independent polls and could win the kind of complete control of the executive, legislative and judicial branches that leaves no room for excuses later on.

Four years ago, President Antonio Guzman of the Revolutionary Party outpolled rightist strong man Joaquin Balaguer in the republic's first nonviolent election in a century, but Balaguer's Army tried to stop the vote count. The tally proceeded only after then-president Carter joined the business community to warn that U.S. aid would be "reviewed" if the vote were not respected. Carter also sent the head of the U.S. military Southern Command here on a brief but meaningful visit.

Jorge Blanco has campaigned on his party's success in institutionalizing civilian democracy but divorces himself from Guzman's economic policies, which were not so successful.

"The PRD is communist," said one woman at an opposition parade. "We are the true friends of the United States. We are voting against hunger." The shouts and signs of her Reformist Party call for a return to power of Balaguer, 75, the one-time protege of assassinated Dominican dictator Rafael Trujillo. Balaguer was virtually installed by the United States after its 1965 invasion.

But Balaguer's once-firm hand is increasingly palsied. Nearly blind from glaucoma "that could easily have been treated if he admitted the problem," according to a sympathetic businessman, he barely campaigned at all and even withdrew briefly from the race in March in an intraparty dispute over his vice presidential candidate. Still, the Reformists are expected to run a strong second.

But Balaguer, said Alejandro Grullon, president of the Dominican Popular Bank, cannot bring back international sugar prices that reached 64 cents a pound in 1974 and are now at nine cents. He cannot exchange the oil prices of 1972 for those that now take half of all Dominican import spending.

The third-running candidate is Juan Bosch, at 73 another grand old man of Dominican politics. Ousted from the presidency in a 1963 coup, Bosch founded the PRD and was once the center around whom all the country's reform-minded young men revolved, including Jorge Blanco. But he left the party long ago and has since served as a sort of national conscience, criticizing parties and politicians across the spectrum.