No political party in power in the world has governed as long as Paraguay's Colorado Party, which has held a tight and sometimes brutal grip on this poor South American country for more than six decades.
But the center-right party is now facing one of its strongest challenges ever in the country's April 20 presidential election.
The emergence of a former Roman Catholic bishop and political neophyte as the front-runner in the race, bitter in-fighting and lukewarm support for its presidential candidate are all threatening the Colorado Party's hold on power.
"For the first time in 20 years, the Colorados are facing the possibility of losing and they're worried," said Marcelo Lacchi, a political analyst at the Center for Studies and Popular Education in Asuncion.
For the vast majority of Paraguayans, the Colorado Party is the only government they've known.
It has ruled since 1947, including the 35-year dictatorship of General Alfredo Stroessner, which was marked by repression, torture and rampant corruption. Human rights group say some 900 people were kidnapped and killed under Stroessner, many of them suspected of being communist sympathizers.
The Colorado Party has drawn comparisons to Mexico's Institutional Revolutionary Party, the world's longest-ruling before it was unseated in 2000 after more than 70 years in power.
Paraguayan polls show the election favorite is Fernando Lugo, a left-leaning political newcomer who quit the priesthood to seek the presidency and is heading a coalition of opposition parties.
Colorado candidate Blanca Ovelar, a former education minister seeking to become Paraguay's first female president, trails in second place, and Lino Oviedo, a former army commander once jailed for leading a coup attempt, is running a close third.
Powerful party machine
In a country notorious for corruption and contraband smuggling, the Colorados have stayed in power in large part because of a well-oiled party patronage machine.
After decades of rule, the party has virtually become synonymous with the state and a part of the national identity.
Colorado members make up most of Paraguay's 200,000 public-sector workers, and they serve as the backbone of the party's powerful get-out-the-vote machine.
Colorado offices are scattered in neighborhoods across Paraguay, resembling community centers where supporters seek medical help, take cooking classes or hold birthday parties for their children.
But critics say public exasperation with the Colorados is growing. Boosted by soy and beef exports, the economy is expanding, but more than 40% of Paraguayans remain mired in poverty.
"In their 60 years in power, what have they accomplished? A military dictatorship and corruption," said Camilo Soares, a candidate for Congress from a leftist party aligned with Lugo. "The chances of defeating them have never been better."
Enthusiasm in the ruling party has been dampened by months of political bickering after a bitter primary election last year was riddled with fraud accusations.
Outgoing President Nicanor Duarte Frutos is unpopular with many Colorado supporters and his backing of Ovelar has opened a rift in the party's ranks.
Santiago Fernandez, a 28-year-old health ministry worker and Colorado activist in the working class Asuncion neighborhood of San Pablo, acknowledged drumming up party support has been difficult ahead of the election.
"We're in a tough situation," he said. "But there is no other party that can lead Paraguay. History has proved that."
Political analyst Milda Rivarola said Paraguay's changing economy has in part chipped away at Colorado support.
For years, the economy was driven by government spending and public works programs. But agricultural exports, fed by strong global demand for commodities, now power the economy. Paraguay is the world's fourth-biggest soy exporter.
"The idea of the state as the country's biggest employer no longer works," Rivarola said. "Economic times have changed."
Still, Lacchi said it was too early to count the Colorados out. He pointed to the 1998 presidential race when the party was deeply divided heading into the vote, but united in the campaign's final days to rally and win.
"There is still a large part of Colorado voters who haven't been captivated and mobilised," he said.