Last-Minute Challenger Tests Menem’s Mettle : Argentina: Defector from president’s party comes from behind, hopes to force runoff vote.

President Carlos Menem has a long lead in the race to win the May 14 elections, but a new dark-horse candidate is coming up from the rear.

Sen. Jose Octavio Bordon, a defector from Menem’s Peronist Party, has emerged almost overnight as the opposition’s best hope for forcing a runoff vote. Noticias magazine recently put Bordon on its cover, calling him “The Peronist Who Could Beat Menem.”

It is still hard to see how Menem could lose, but Bordon is just getting started.

“Two out of three Argentines don’t want to vote for Menem again,” Bordon, 49, said in an interview. “What is the problem? That people still don’t have an alternative. My candidacy has given birth to the hope that it could be me.”

Before Bordon’s star began rising, the opposition’s leading contender was Horacio Massaccesi, a member of the Radical Party. But Massaccesi has some serious handicaps.

The Radicals still have not overcome the discredit they incurred by leaving the economy in a state of hyper-inflation after governing from 1983 to 1989. Top Radical leaders, including former President Raul Alfonsin, chose not to run for president this year and have been less than overwhelming in their support for Massaccesi, a lackluster politician who is governor of the southern province of Rio Negro.

Lately, Massaccesi’s disorganized campaign has wilted as public attention has focused on serious financial problems in his provincial government.

Bordon, in contrast, has a reputation for administrative efficiency from his past tenure as governor of Mendoza province. He is not charismatic, but on television he projects moderation and common sense. A sociologist, he calls himself a Christian humanist in the John F. Kennedy mold.

Last year, Bordon joined forces with another Peronist renegade, Congress member Carlos (Chacho) Alvarez, who heads a center-left coalition of small opposition parties. That grouping and Bordon’s fledgling movement, called Pais (the Spanish word for country ), formed a new coalition known as Front for a Country in Solidarity, or Frepaso.

In a caucus in February, Bordon narrowly defeated Alvarez for the presidential nomination. Alvarez is the vice presidential candidate.

Bordon’s surprise victory put him in the media spotlight, getting his campaign off to a fast start.

A recent poll in Buenos Aires gave Bordon 24% of the voter preference against 40% for Menem, 8% for Massaccesi and 4% for right-wing candidate Aldo Rico, a cashiered colonel who once led a rebellious group of army officers. In the poll, by Mora y Araujo Noguera Associates, 24% of those interviewed said they were undecided or would not vote for anyone.

To avoid a runoff, Menem must win at least 45% of the votes, or 40% with a 10% lead over the runner-up. Menem’s strategists are counting on a divided opposition to keep any challenger from breaking the 10-point barrier.

Menem’s economic policy, which has brought stability and growth, is the pillar of his popularity.

In the last two months, a financial scare has sharply reduced bank deposits and stock prices, but analysts say the crisis has not undermined support for Menem so far.

Bordon charges that corruption, unemployment and inequality have all grown on Menem’s watch.

“The time for Menem is over,” Bordon said. “Now we need more austere and efficient administrators.”