BUENOS AIRES — Argentina Wednesday lost one of its most powerful politicians, former President Néstor Kirchner, who suffered a heart attack.
Kirchner, the husband of President Cristina Fernández de Kirchner, died early Wednesday near his home in the Patagonian city of Calafate where he and his wife were waiting to be counted in the national census.
Kirchner served as president from 2003-2007 and is credited with leading the nation out of a punishing economic crisis, reopening dictatorship-era human rights cases, and bucking the international community as he built stronger regional ties.
A congressman and leader of the center-left Justicialista Party, either Kirchner or his wife were expected to run for the presidency in 2011, extending the family legacy.
Now those plans are in doubt, as analysts said Kirchner's death could fuel a shake-up in the party.
Kirchner, 60, had been ailing for months and had been treated twice this year for heart-related issues. He was rushed to the hospital early Wednesday and died at 9:15 a.m., the presidency reported.
Despite his medical problems, Kirchner maintained an active political agenda.
He was the head of his powerful Peronist party and was recently appointed the first secretary general of the Union of South American Republics, or UNASUR. That organization played a leading role in defusing tensions between Colombia and Venezuela earlier this year and rallied the region behind Ecuadoran President Rafael Correa when a police uprising threatened to topple him last month.
But in Argentina, he was seen as the power behind the throne.
Buenos Aires-based analyst Carlos Germano said Kirchner was central to his wife's presidency — her closest confidant and her most powerful supporter. His death is likely to force her to build new alliances and could spark challenges within her own party, he said.
"The political scene is extremely complicated," Germano said. "She's not going to have much time to grieve."
But on Wednesday, even some of Kirchner's harshest critics were putting politics on hold.
Julio Cobos is the vice president of Argentina and an opposition member who has had frequent run-ins with the presidential couple.
"A good president has gone and we need to face this situation in the best way possible," he told local TV.
Wednesday was a holiday in Argentina and citizens were asked to stay home to be counted in the census. That left the streets eerily barren for most of the morning. But as the news spread, people gathered in front of the presidential palace where they laid wreaths and hung placards reading "Be strong Cristina" and "Your country consoles you" — as flags flew at half mast.
Many politicians were caught off-guard in their home states, and were rushing back to Buenos Aires for the wake, scheduled to be held at the presidential palace on Thursday.
Kirchner is also survived by two adult children, Maximo and Florencia.
Brazil and Venezuela joined Argentina in declaring three days of national mourning, as condolences poured in from around the globe.
"Néstor Kirchner played a significant role in the political life of Argentina and had embarked upon an important new chapter with UNASUR," President Barack Obama said in a statement. "My thoughts and prayers are with President Fernández de Kirchner and their children."
On his Twitter page, Venezuelan President Hugo Chávez — a personal friend of the president — expressed his grief.
"Oh my dear Cristina," he wrote. "How much pain! What a great loss for Argentina and our America! Long live Kirchner forever!!''
The Organization of American States held a minute of silence.
Kirchner came to power in 2003 when the country was in economic and political turmoil. Many Argentines tolerated his left-leaning politics because he managed to tame the chaos, said Enrique Zuleta Puceiro, a university professor and political analyst.
"He had to govern at a very difficult time and he was able to rebuild everything," Zuleta Puceiro said. "Although many did not share his ideas, everybody recognizes his commitment, efficiency, heroism, independence and courage."
Recent polls suggest that both Cristina Fernández and Néstor Kirchner were running about ahead of their nearest rivals. Even so, six out of 10 Argentines also say they were looking for a break from the couple, who have held the presidency for a combined eight years.
While it could be days or weeks for the political implications of his death to shake out, Kirchner's absence will be felt immediately, said Daniel Kerner, an analyst with New York-based Eurasia Group.
"The biggest uncertainty is probably in terms of economic policy. Nestor Kirchner was the country's main decision-maker, and ministers, secretaries and advisors tend to have a rather marginal role in shaping policy direction," he wrote. "Thus, without him, it's not very clear how the government will work."
Even so, Kerner said Fernández will probably see her position strengthened amid a wave of public sympathy.
Zuleta Puceiro, the political analyst, said Fernández has proven to be a resilient politician.
"I don't think there will be a problem with Fernández de Kirchner after the pain is gone," he said. "We do not know how the president will react but she is a woman accustomed to using crisis as a virtue. She has the ability to beat the odds."
(Wyss reported from Miami. Miami Herald Special Correspondent Angeles Mace reported from Buenos Aires.)