By Eliana Raszewski and Nicolás Misculin
BUENOS AIRES (Reuters) - After decades pulling political strings behind the scenes as a cabinet chief and strategist for Argentine presidents, Alberto Fernandez now aims to win the top job himself.
But rather than a power grab, the unexpected presidential bid announced on Saturday appears more a strategic maneuver orchestrated by his political patron, former President Cristina Fernandez de Kirchner, who is running as vice president.
Many had thought she would be the main challenger to incumbent President Mauricio Macri in the Oct. 27 election.
Putting Alberto Fernandez, a 60-year-old lawyer, at the top of the ticket is aimed at improving chances of victory for the Peronist party and in keeping with his long service as a mostly loyal party operative, analysts said.
Alberto Fernandez, a moderate Peronist seen in political circles as a consensus builder, will now need to unite a fractured opposition to take on center-right Macri whose popularity in the polls has tumbled amid economic crisis in South America's No. 2 economy.
"Alberto Fernandez is a negotiator, pluralist, and dialogist," said political analyst Ricardo Rouvier,
"It is a strategic decision of Cristina to make a final push to try to build a winning electoral alliance and show herself in a more moderate and softened way."
Alberto Fernandez has worked for much of his political career alongside Cristina Fernandez and her late husband, Néstor Kirchner, who also held the presidency.
Well connected in the powerful Peronist movement, Alberto Fernandez helped an almost unknown Kirchner when he was governor of Santa Cruz province to expand his political support and take the presidency in 2003.
Kirchner made him chief of staff for his 2003-2007 term, and he continued in that role for the first months of Cristina Fernandez's administration, which ran from 2007 to 2015.
Alberto Fernandez resigned in 2008 after the government suffered a legislative defeat in a confrontation with the powerful farming sector that kept the country and the markets in suspense for months.
He even became a harsh critic of Cristina Fernandez's management and forged ties with other factions of Peronism at the time who were opposed to her ruling party.
"Alberto I've known for over 20 years and we've had also our differences," Cristina Fernandez said in a video on social media announcing their joint bid.
However, in recent months Alberto Fernandez again became her main political negotiator, trying to help her generate support from the more moderate wing of the opposition.
That fell short with many concerned about Cristina Fernandez's divisive style and the shadow of a corruption trial hanging over her. One trial is due to begin next week, though as a senator she currently has immunity from arrest.
"Alberto is not an electoral politician; Alberto is an operator in the shadows," said a Peronist source who knows him. Despite her lower rank on the ticket, Cristina Fernandez is a rock star politician who commands huge crowds.
That made it perhaps unsurprising that news broke not from the presidential hopeful but from Cristina Fernandez on social media, where she said she had "asked" him to lead the alliance.
"In what country or parallel dimension does the vice presidential candidate announce who will be the candidate for president?" asked one local journalist on Twitter.
Alberto Fernandez's dialogue style seems however to already be bearing fruit. On Saturday, an important leader of another Peronist faction, Sergio Massa, said he was willing to negotiate an agreement with Cristina Fernandez's wing.
Alberto Fernandez posted replies on Twitter to well-wishers, saying he would work to pull Argentina out of its crisis.
"I'm filled with joy at being able to work together to restore dignity to millions of Argentines that this government has plunged into marginality and poverty," he wrote.
(Reporting by Eliana Raszewski and Nicolas Misculin; Writing by Adam Jourdan; Editing by Cynthia Osterman)