Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Argentine Election Season Begins with Much-watched Primaries Associated Press BUENOS AIRES, ARGENTINA - Argentines are entering the tightest presidential race since the return of the country's democracy with conservative President Mauricio Macri facing an opposition ticket including ex-President Cristina Fernandez, and primary elections Sunday are expected to provide a hint of who might win October's vote. Party primaries are closely watched in Argentina because they are held simultaneously and voting is obligatory, so they are seen as referendum on candidates' popularity -- effectively an early poll involving the entire electorate. This year's primaries will be "a great orchestra rehearsal (for the Oct 27 election) in which we are going to see which instruments will play, which will play loudly and which will be silenced," said Luis Tonelli, a political science professor at the University of Buenos Aires. He said he hasn't seen an electoral process "this close and with this much uncertainty" since a seven-year military dictatorship ended in 1983. He described it as "a tossed coin hanging in the air." Markets could go up or down depending on whether the business-friendly Macri or center-left ticket of Alberto Fernandez and Cristina Fernandez poll favorably on Sunday. Alberto Fernandez was the former president's chief of staff during her initial term from 2007-2011, and she surprised many people when she announced that she would be the vice presidential candidate while he runs for president. If no candidate wins outright in October, there would be a November runoff. .