The BBC's Emilio San Pedro travelled across the region for Radio 4's A New Axis of Power, to see just how close Latin America's leaders are to each other.

Concerns of the poor are becoming part of the political mainstream

Lisandro Perez is the leader, or jefe civil, of the 23 de Enero district of the Venezuelan capital, Caracas. If you were looking for a place to confirm an impression that a red tide is sweeping South America a visit to his office would leave you in little doubt.

Pictures of socialist and communist revolutionaries past and present adorn the walls. The pile of paperbacks on his desk includes ones about Vladimir Lenin and Karl Marx. Next to the books lies a hood - it is the emblem of his violent left-wing guerrilla past as a member of the Tupamaro movement.

The movement is now an active social militia, Mr Perez says. And that has seen him on the streets, notably to defend President Chavez against the coup attempt in 2002.

"We need people who are fighters and who believe in social change and above all in socialism," he says.

Mr Perez's nickname - the one I heard him called as we walked around his impoverished district on the hills of Caracas - is a blast from the revolutionary past: Mao.

"I consider myself to be a Marxist-Leninist and I follow a very specific path which includes the teachings of Mao Zedong," he tells me.

"I always carry his writings along with me and they form a part of my daily life. I would say I'm a follower of his in the same way that I follow President Chavez."

Lula conservative?

Two thousand seven hundred miles away, in Brazil's biggest city, Sao Paulo, newspaper columnist Clovis Rossi is teasing his editor.

One of the most important bankers in Brazil told us that he would like to erect a statue to Lula in front of his bank's building! Clovis Rossi Brazilian columnist

Mr Rossi works for the Folha de Sao Paulo newspaper, which says it has the biggest readership in Brazil. "We need to print a correction!" he says.

Why? Mr Rossi says that a headline the paper printed when working-class hero Lula Inacio da Silva became president in 2002 is wrong.

"It says 'First leftist elected in Brazil', but his government is miles from being leftist," he says.

"I would even say if you take the word conservative, as meaning preserving the status quo... Lula is the most conservative of the presidents we have had since redemocratisation 20 years ago."

Lula's maintenance of the economic regime of his predecessor has earned him the devotion of bankers, Mr Rossi says. "One of the most important bankers in Brazil told us that he would like to erect a statue to Lula in front of his bank's building!"

Mr Chavez and Lula are part of the shift to the left, but in many ways they could be described as worlds apart. You could say the same of Evo Morales, Bolivia's president, and Michele Bachelet, newly-installed as president of Chile.

It has been very easy for the populist rhetoric to establish an 'Us versus them' message Felipe Noguera Argentine political consultant

For Lula and his government, the pursuit of economic stability is necessary to tackle poverty and inequality, and they cite success in both, backed by a range of social programmes.

In Bolivia and Venezuela you are much more likely to find business people - especially from international oil firms - worrying that the climate for making money is being soured by those respective governments.

But there are trends that seem to be sweeping the region, and on which politicians and analysts alike seem to share a similar perspective: that the concerns and plight of the poor and marginalised have become part of the political mainstream.

'Political vacuum'

Margarita Lopez Maya is a Caracas-based academic who is sympathetic to Mr Chavez. In the light of Mr Morales's electoral success in Bolivia she says:" What's happening in Latin America, from my historical perspective is that we are finally arriving to the point where we are going to have a social revolution. We are finally going to see that the people are equal.

"That's what we are trying to accomplish. We tried to do that in the 20th Century. But the immense majority of the people were still not citizens. They were second class citizens or non-citizens if you talk about the indigenous people," she argues.

In the trendy dockland area of Puerto Madero in Buenos Aires, political consultant Felipe Noguera bemoans the politics of Mr Chavez and his Argentine counterpart, President Nestor Kirchner.

President Kirchner has attacked the IMF for the woes his fellow country people have suffered as a consequence of the 2001-2002 economic crisis.

Ms Bachelet and Mr Morales: Both left-leaning but worlds apart

The IMF is a whipping boy for Mr Chavez as well - representing what he describes as "neo-liberalism", an exploitative form of capitalism that impoverishes rather than enriches ordinary people.

Mr Noguera says that this is populism. But he admits it is filling a political vacuum, with sentiments that have echoes of the thoughts of Ms Lopez Maya in Caracas.

"I don't think we've had the same growth of an international idea of how to tackle poverty. Therefore, it has been very easy for the populist rhetoric to establish an 'Us versus them' message," he says.

Mr Noguera says he disagrees with the idea that the Washington Consensus - a set of policies put forward by some economists as a formula for promoting economic growth - or the IMF policies failed.

"They succeeded in what they set out to do, which was to stop the macro-economic crisis and to regenerate some growth and some sense into the economies.

"What they failed to do was establish the new objectives of fighting poverty."

He says populist politicians are being supported by the high price of commodity prices - for example, oil exports in Venezuela and agricultural produce in Argentina - and that historically this recipe has failed.

'Hope'

Mercedes Marco del Pont is an Argentine deputy in Mr Kirchner's Front for Victory Movement, and a long-standing critic of the IMF. Not surprisingly, she disagrees.

Popularity is not the same thing as populism, she says.

The oil is ours! Mercedes Shanty town dweller, Caracas

"It's true that the president enjoys a very high level of popular support, but this isn't the result of him taking populist measures. It is owing to the fact that we have a president who maintains fiscal discipline and gets involved directly in negotiations with various social and economic players," she says.

"It is important to recognise this as a necessary characteristic in countries such as Argentina, where the state disappeared from the centre-stage for a long time," Ms Marco del Pont argues.

Whatever their differences in policy execution, what the left-leaning presidents of various hues are doing is tapping into and articulating the hopes and aspirations of those that could be seen as dispossessed or marginalised.

It was brought home to me, when I climbed up the narrow steps between the ranchos - the shanty dwellings - back in Mao's 23 de Enero district in Caracas.

I met Mercedes, whose father built her shack 48 years ago.

She and her family are hoping to have the rudimentary and flimsy structure of hardboard and corrugated iron replaced by a building of bricks. They are on a government waiting list for the home.

Under President Chavez, says Mercedes, they at last have hope. Yes their conditions are precarious, but things improve little by little.

And of Venezuela's great oil wealth that gives President Chavez the spending power for his social programmes, she has this statement: "The oil is ours!"