JOHANNESBURG, South Africa -- As South Africa's governing party moves closer to picking its next leader, it will do so without the man widely viewed as the country's moral compass.

Nelson Mandela, who remains hospitalized with a lung infection, led the African National Congress political party to victory in the nation's first truly democratic election in 1994 through a principled show of magnanimity toward the country's racist former rulers, despite spending nearly three decades in prison.

Today, his party appears grounded by corruption allegations, as current President Jacob Zuma has faced rape charges and questions about enriching himself through his public office.

The more Mandela fades, the more some in South Africa worry the ANC is ceding the higher moral ground it once held.

"We know that even though the dream of a just, nonracial and prospering democracy is temporarily in eclipse -- being throttled by the actions (or lack of it) of a generation of leaders that seems to have largely lost its moral compass," a recent letter that religious leaders sent to Zuma reads. "The people of South Africa are capable of rising to reclaim their future."

Mandela, 94, was admitted Saturday to 1 Military Hospital near South Africa's capital, Pretoria, for tests. Government officials later said he was suffering from a chronic lung infection. He had an acute respiratory infection in January 2011 and the chaos surrounding Mandela's stay at a public hospital saw the South African military take charge of his care and the government control the information about his health.

On Wednesday, presidential spokesman Mac Maharaj issued a short statement confirming Mandela remained hospitalized for a fifth day.

"Doctors attending to former President Mandela have reported that he has made progress during the past 24 hours and they are satisfied with the way he is responding to treatment," Maharaj said in the statement. It offered no other details, nor any suggestion of when Mandela could be released.

Mandela has a history of lung problems. He fell ill with tuberculosis in 1988 toward the tail-end of his prison years. While doctors said at the time the disease caused no permanent damage to his lungs, medical experts say tuberculosis can cause problems years later for those infected.

Each day Mandela is hospitalized causes growing concern in South Africa, a nation of 50 million people that reveres the aged leader for being the nation's first democratically elected president who sought to bring the country together after centuries of racial division.

Mandela largely retired from public life after serving one five-year term as president, and lived a private life, although he did campaign against HIV/AIDS. He last made a public appearance when his country hosted the 2010 World Cup soccer tournament. The Nobel laureate has also grown more frail in recent years, with his grip on politics in the nation ever slackening.

In Mandela's place, Zuma, 70, now leads the ANC. Next week, the party will hold a convention in Mangaung that will see it elect its next leader. Whoever is picked likely will have an automatic ticket to South Africa's presidency in the 2014 election as the ANC faces no strong challenge from any of the country's opposition parties.

Zuma probably will hold onto his position, despite his falling popularity in the nation. Many have grown angry recently over the millions of dollars of government-paid improvements made at his private homestead. Zuma also was fired as the country's deputy president in 2005 after his financial adviser was convicted of trying to elicit a bribe for Zuma to deflect investigations into the arms deal.

Local newspapers also repeatedly raise claims about Zuma being unable to manage his personal finances and relying on friends to bail him out. That includes, allegedly, a payment of 1 million rand ($145,000) from Mandela himself days after he was fired as deputy president.

Zuma also previously faced intense criticism over his sexual activity, including being acquitted of raping a family friend. He also outraged AIDS activists by testifying that he had unprotected, consensual sex with the HIV-positive woman and then took a shower in the belief that it would protect him from AIDS.

After that, Zuma later publicly announced the results of his own HIV test and has pushed for a strong response to the AIDS epidemic in South Africa.

However, as the letter from religious leaders show, many view Zuma as merely the tip of the corruption running through the ANC, whose lower-level officials in government have been ensnared in a number of corruption and mismanagement allegations in recent years.

Confronted with the letter published across newspapers and discussed in television and radio broadcasts, Zuma's spokesman Maharaj issued a statement dodging the claims with a simple punch line: "Building a better society is the responsibility of every South African."