MONTEVIDEO, Uruguay — A former guerrilla fighter has achieved through the ballot box what he could never earn by bombing, kidnapping and attacking his political enemies — the power to legitimately lead a nation.

Jose Mujica won 53 percent of the vote, to 43 percent for Luis A. Lacalle, with 97 percent of the vote counted, the electoral court announced today.

Mujica seemed like he could hardly believe it himself in his rousing victory speech, delivered as rain drenched thousands of supporters along the Ramblas, Montevideo’s coastal avenue.

“The people gave us this victory!” Mujica shouted, moving back and forth as aides struggled to cover the 74-year-old with umbrellas. “There are those who believe that power is up above, and they don’t notice that it’s actually in the hearts of the great masses. Thank you! It cost me an entire life, perhaps, to learn this. Thank you, and until forever!”

Mujica repeatedly denied Lacalle’s claims that he would hijack Uruguay’s stable parliamentary democracy and install a radical socialist state modeled on Hugo Chavez’s Venezuela. He said he’s inspired instead by Brazil’s Luiz Inacio Lula da Silva, who also rose from militancy, as a union chief, to become a popular centrist at the helm of government.

And he said he would continue the policies of President Tabare Vazquez, who enjoys a 71 percent popularity rating as he prepares to leave office March 1.

Lacalle conceded that Mujica will be the president of all Uruguayans, but also invoked the fears of his supporters by promising to be “soldiers for the truth, custodians of the institutions and defenders of the laws” during his rival’s term.

The Tupamaro guerrillas, co-founded by Mujica, caused so much chaos in the 1960s that Uruguayans initially welcomed a dictatorship that ruled from 1973 to 1985. Mujica spent all that time in prison, enduring torture and solitary confinement for killing a policeman — a crime he denies committing. He says prison cured him of any illusion that armed revolution can achieve lasting social change, and he now rejects the “stupid ideologies” of the 1970s.

Mujica’s future wife, fellow Tupamaro Lucia Topolansky, also emerged from prison committed to transforming the rebels into a legitimate political movement that became the driving force within the Broad Front, a center-left coalition that pulled more than 20 leftist factions together five years ago to give Vazquez a presidential victory. It was the first time in 150 years that the office wasn’t won by Lacalle’s center-right National Party or the right-wing Colorado Party.

Many voters said the single five-year term required by Uruguay’s constitution wasn’t enough to consolidate the successes of Vazquez, who imposed a progressive income tax and used the revenue to lower unemployment and poverty, provide equal access to health care to everyone under 18 and steer the economy to 1.9 percent growth this year even as many other economies shrank.

Lacalle, a scion of Uruguay’s political elite, championed privatizations during his 1990-95 term and had vowed this time to eliminate the income tax and “take a chain saw” to state bureaucracies. But he also acknowledged Vazquez’s successes in the economy.

The Broad Front held on to a narrow majority in Congress, where Topolansky earned the most votes in the Senate and will therefore be third in line to the presidency, after Vice President-elect Danilo Astori.

As for Mujica, he still has the appearance of an anti-politician, a gruff old man more comfortable driving a tractor on his farm than shuffling through marbled halls. Topolansky has said she’ll only reluctantly endure the protocols of a first lady.

As Uruguay’s first couple, they could finally taste luxury in the official presidential residence in Montevideo. But the couple have said they prefer to stay in their “chacra,” a little flower farm in the Rincon del Cerro, a working-class community with dirt roads and small plots on the edge of the capital.

Vazquez also chose to stay in his own home and use the mansion only for official functions.