MANAGUA, Nicaragua — President Daniel Ortega appeared headed for a landslide re-election victory Monday, an outcome likely to cement Sandinista leadership — and Ortega's dominance of Nicaragua — for years to come

The triumph displayed Ortega's transformation from a fatigue-clad socialist to a populist who still lashes out at the United States but embraces Roman Catholicism, oversees a growing personal fortune and sticks to market and investor-friendly policies.

With about 86 percent of precincts reporting, Ortega was leading at about 63 percent over 31 percent for Fabio Gadea, a radio executive who led a broad alliance of those opposed to Ortega's drift toward authoritarian rule. A third candidate, former President Arnoldo Aleman, held 6 percent.

Perhaps more significantly, early results showed Ortega's Sandinista Front winning 59 seats in the 92-seat National Assembly, a "super majority" that would allow him to change the country's Constitution to permit indefinite re-election. It also would legally free his hand in naming Supreme Court magistrates and other functionaries without interference and would enshrine local Sandinista neighborhood committees known as Citizen Power Councils that channel aid.

Reports of voting irregularities were persistent but not vast. Of the two major international observer teams, one from the Organization of American States backtracked Monday, calling problems its team faced in entering some polling places "inconveniences" but noting that didn't find "relevant anomalies."

"In Nicaragua yesterday, democracy and peace took steps forward," OAS Secretary-General Jose Miguel Insulza said in a telephone call to Ortega, a statement said.

Ortega's supporters poured into the streets late Sunday night to celebrate victory as election results trickled in.

"This is a victory for Christianity, for socialism and for solidarity," Ortega's wife, campaign manager and virtual co-president, Rosario Murillo, told supporters. "Through God's hand, Nicaragua won."

Ortega has presided over economic expansion fueled in part by nearly $2 billion in assistance since 2007 from Venezuelan President Hugo Chavez, and Venezuela was the first to congratulate the 65-year-old former guerrilla.

Chavez's government saluted Ortega's "convincing victory" and pledged continued support for a government that it said was working for "the restitution of people's rights."

Striking a contrary note, Rep. Ileana Ros-Lehtinen, a Florida Republican who chairs the House Foreign Affairs Committee, called Sunday's vote "a complete sham."

"According to the Nicaraguan Constitution, Ortega was not eligible to run for another term as president. But he forced his way onto the ballot through a corrupt scheme that trampled over Nicaraguan constitutional mandates," Ros-Lehtinen said in a statement.

"He has clearly learned from his dictatorial buddies in the region, like Chavez, who is an expert at trampling democracy."

Claims of widespread fraud in 2008 municipal elections that allowed Sandinista candidates to take office in dozens of cities and towns led Washington to cancel most development aid to Nicaragua.

For this election, Ortega barred all but two major international observer teams, from the OAS and the European Union, and withheld approval for two domestic civic election monitor groups, claiming they were biased.