The power couple, who hail from the famous left-leaning Peronist party and whose political leadership has been divisive, is widely believed to have shared a co-presidency of sorts, with Kirchner taking on the political role while his wife dealt with policy. His death quiets a prominent and powerful voice within her administration while clearing the way for a wild card in the upcoming 2011 presidential election.

“He was not only the former president but also the strongest political support behind the Cristina presidency,” said Pablo Ava, an independent political consultant in Buenos Aires. “He was president of the Peronist party, and also he was the main candidate considered by the Peronist party for next year's election. This has a big impact in current Argentine politics.”

While he has his fair share of critics, most agree that the Kirchner legacy is clear. While he alone did not shepherd the country out of economic distress – his predecessor set the course, and high prices of soybeans also helped – he mostly gets the credit for impressive economic growth that saved the country from collapse.

Human rights workers also praise his commitment to their causes, including trials for former dictator-era figures who had previously enjoyed amnesty.

But the Kirchner power couple has also been seen recently as overly divisive, generating conflict whether with farm unions or the media or opposition figures.

It is a style that worked well during his administration in the midst of crisis, but one that has not served his wife well, says Mark Jones, who advises the US government on Argentine affairs and is a professor of political science at Rice University.

His death might force the current president into a more consensual style.

“She will have a more moderate approach,” Jones said. “And it makes the probability that she will continue for [another] four years greater.” Power couple

The Peronist couple rose to power from their base in the Patagonian province of Santa Cruz, and they have long ruled hand in hand. During the last presidential election cycle in 2007, many speculated that Kirchner, who enjoyed approval ratings of over 65 percent, stepped aside so that his wife could run and he could return to power immediately afterwards.

Under Argentine law, presidents can serve unlimited terms if they are not consecutive. To critics, the two were attempting to form a rotating presidency in which their reign could last permanently. At the very least, the strategy contributed to the perception that the two were never lame-duck presidents.

“This is dramatic. This changes the dynamics of the 2011 election campaign, because the only stable point within the [race] was the fact that Nestor Kirchner, or if not him his wife, would be running for re-election,” Jones said.

His death could also dramatically change the nature of governance and policymaking in her final year in office.

Of the two, Mr. Kirchner was considered the savvy political operator, managing disparate political views and confrontations with mayors, or governors, union members, or leaders of social movements. While he dealt with the nitty-gritty, she took the broader view of the country's affairs.

“The political leg of the administration will be very stressed these days,” says Mr. Ava. “There will be a very big empty place.”