CARACAS -- Henrique Capriles Radonski has taken on President Hugo Chávez from congress, the governor’s mansion and from jail. Now, he’s hoping to continue that fight in the national arena.

On Sunday, Venezuelans head to the ballot box to choose a single opposition candidate to battle Chávez for the presidency in October.

Most polls give Capriles, the governor of Miranda state, a 15 to 20 point lead over his nearest rival in the five-way race.

Wiry and intense, Capriles, 39, has made a name for himself as a hands-on leader with a workaholic streak. During recent flooding, he was photographed in chest-high water helping constituents. At campaign rallies, he has the politician’s knack of making just enough eye contact to satisfy supplicants as he plows through massive crowds.

It’s that energy that he says will allow him to beat the 57-year-old Chávez, who has stepped up his TV appearances as he recovers from an undisclosed form of cancer.

“That horse is tired and this horse is full of energy,” Capriles told reporters recently. “We are going to travel this country from point to point...You win the race on the ground not on television.”

Capriles’ political sprint has helped give him a comfortable lead over his nearest rival, Pablo Pérez, the governor of Zulia state. Further behind in the race are legislator María Corina Machado, Venezuela’s former permanent representative to the United Nations Diego Arria and Pablo Medina, a one-time Chávez ally turned foe.

After years of squabbling that played into Chávez’s hand, the coalition of opposition parties is hoping a unified front will give them the momentum necessary to capture the presidency. All the contenders in Sunday’s race have pledged to back the winner.

But the cooperation hasn’t started yet. On the campaign trail, Capriles has pledged to be tough on crime, loosen state controls and create a business-friendly environment. But he has also promised to improve social programs, or the “missions” that have been one of the backbones of Chávez’s popularity.

“The sense that the quality of these programs has deteriorated is unanimous,” said Capriles, who advocates auditing the initiatives — which include free food, housing and subsidies to the elderly, among others — to see if they’re effective.

In Miranda, 60 percent of the free medical clinics that Chávez began rolling out in 2003 have been shuttered, he said. “What do I offer? Let’s get these programs working again. And why stop there? Let’s take them even further.”

In polarized Venezuela, giving Chávez any credit is anathema to the opposition. Capriles’ willingness to do so has exposed him to attacks by his rivals. But his message has resonated among those weary of the political divide.

In this primary race, the anti-Chávez hard-liners have been polling near the bottom, said John Magdaleno, the director of Politi, a political consulting firm.

“If people still think that confronting Chávez head on works, here’s the evidence that it’s a failed strategy,” he said. And even though social issues, such as healthcare, education and housing, are Chávez mainstays, the opposition is wise to address them.

“If your competitor is strong in some areas and those areas are vital for the majority, you have to try to beat that monopoly,” he said. “You have to steal his flags.”