BUENOS AIRES — The party of ailing Argentine President Cristina Fernandez de Kirchner lost ground in Sunday's congressional elections, in effect killing chances that loyalist legislators would amend the constitution to allow her to run for a third term in 2015, as many supporters have urged her to do.
If trends continue, Fernandez's Victory Front party could maintain its majority but win about five fewer seats than she and her allies now control in the Chamber of Deputies. Their preelection tally was 134 out of 257 seats, far less than the two-thirds needed to approve a constitutional amendment.
The president's favored candidates and allies also appeared to be losing ground in the 72-seat Senate, where her bloc now controls 40 seats. To amend the constitution, she would need 48 Senate seats.
With 72% of the ballots counted nationwide, the president's party and allies were garnering just 33% of the vote, down from the 54% her bloc won in 2011 when she was elected to a second term.
Fernandez's cause was hurt by rising crime, corruption and inflation, and by her absence from the campaign trail since Oct. 8, when she underwent surgery to repair a brain hemorrhage. She has not been seen or heard from since, and her administration has released few details about her medical condition except to say that her convalescence is proceeding normally.
After casting his ballot in the southern city of Rio Gallegos on Sunday morning, the president's son, Maximo Kirchner, told reporters that his mother is improving and that expressions of support "do us a lot of good."
Fernandez's doctors ordered her to take 30 days off to recover and prohibited air travel during that period, which meant she could not travel to campaign events or vote Sunday at her home base in Santa Cruz in southern Argentina. In recent years, Fernandez, 60, has been plagued by health problems related to high blood pressure.
The election results show a sharp weakening of her political power. The widow of her immediate predecessor, President Nestor Kirchner, who died in 2010, Fernandez swept to a second term in 2011, with her party's candidates riding her coattails to congressional majorities in both houses.
Fernandez has not formally announced her intention to seek an amendment that would permit her to run for a third term, but some analysts said they thought it likely if she had adequate legislative support.
"Like all political phenomena, you can't single out just one cause," said Cecilia Mosto, political analyst at the Buenos Aires consulting firm CIO, when asked to explain the president's weakened influence. One reason was perceived ineptitude of government ministries in the management of public policies and services, she said. Another was the horrific wreck of a Buenos Aires commuter train in February 2012 at the Once railroad station, which killed 51 and injured hundreds.
"A big blow to Cristina's image was the Once disaster," Mosto said, because it exemplified government corruption and mismanagement. "The sad event synthesized and exposed in the worst possible way her weaknesses."
Special correspondents D'Alessandro reported from Buenos Aires and Kraul from Bogota, Colombia.