Milkmen were once a common sight on the streets of American cities. They began to disappear a generation ago when convenience stores became a cheaper alternative, as new manufacturing processes increased the shelf life of a pint of milk. Now milkmen are making a comeback with new delivery services opening up across the country.

One of the most recent revivals is in Portland, Oregon, where Local Farmers Delivery launched earlier this year. After a successful start the company is already expanding its delivery area. While the price may be higher, customers get to support local dairy farmers and the delivery chain from a farm to a kitchen is shorter and faster. The new generation of milkmen also understands the value of nostalgia. Many of the milkmen in the US dress up in classic white uniforms, bow ties and hats when delivering milk in glass bottles – bright and early, of course.

Canada’s vast oil sands are remote, which means oil companies are desperate for export pipelines. Environmentalists have delayed expansion of the Keystone pipeline system to the US Gulf Coast. Looking west, Enbridge Inc proposed a pipe over the Rocky Mountains to the Pacific in 2002. It was approved in June but opposition continues.

There are also plans to increase shipments to the Atlantic, most notably TransCanada’s Energy East project to Ontario, Quebec and New Brunswick. It has also drawn protests. If opponents prevail, billions of barrels of crude will be left in the ground, suiting climate-change activists just fine.

After decades of right-wing presidents cherry-picked from the elite, South American politics lurched to the left. The so-called “pink tide”, a sea change marshalled by populist leaders, was sparked by the appointment of Venezuela’s Hugo Chávez, who assumed power in 1999. Subsequent shifts followed in Brazil under Luiz Inácio Lula da Silva, Argentina under Néstor Kirchner, Bolivia under Evo Morales and Ecuador under Rafael Correa.

Fast-forward to today and the South American left – from the social democracy of Chile to the indigenous activism of Bolivia, via the populist personalismo of Ecuador and Argentina – seems more dominant than ever. Indeed, elections scheduled for October in Brazil, Uruguay and Bolivia look unlikely to rattle this status quo. Or that’s how it had seemed until recently.

Two of the three incumbents in October’s vote are standing for re-election: Bolivia’s Morales – a former coca-leaf union leader – and Dilma Rousseff in Brazil. Of the two, Morales – full-time president and part-time first-division footballer – has an easier ride. The president has a wide support base among the country’s indigenous Aymara and Quechua communities that make up the majority of the population. He changed the constitution back in 2009 to give them more rights, also clearing the way for him to run for an unprecedented third term.

“There has been a fundamental restructuring and the awakening of a new section of the population there,” says Christopher Sabatini, senior director of the New York-based Americas Society. “It has left the opposition in tatters.”

The race for top office is far more open in Brazil after more than a year of protests linked to the staging of the football World Cup. The excessive spending on stadiums such as the Arena de Amazônia in Manaus – its raw material shipped from Portugal at huge expense ­– highlighted the flagrant inequalities that a decade of left-wing rule had failed to quash. There have also been corruption scandals – tales of backhanders and inflated contracts – at the heart of Petrobras, the state-run oil company that Rousseff used to chair.

Then a tragedy rattled things further: the death of Eduardo Campos in a plane crash on 13 August. The former cabinet member in Lula’s government had been the Socialist party’s presidential candidate.

Although Campos was trailing Rousseff – and was third in polls behind centre-right candidate Aécio Neves – his death has complicated Rousseff’s re-election due to the nomination of Marina Silva as Socialist successor. A charismatic politician from a poor Amazonian rubber-tapping family, Silva made a name for herself during the 2010 elections when she finished third, focusing on green and indigenous issues. This time she is expected to galvanise a segment of the electorate frustrated by squandered opportunities during Brazil’s boom years.

After the news of Campos’s death, US political consultancy Eurasia Group cut the chances of Rousseff’s re-election to 55 per cent. The first poll released since the air disaster suggested a technical tie. “Dilma is in trouble; Marina Silva blows this contest open,” says Sean Burges, a Brazil expert from Australia’s National Centre for Latin American Studies in Canberra. “People are unhappy. The party has been in power for 12 years and some feel the need for change.”

Many commentators still believe that Rousseff has done enough, even if she will probably have to go to a second round. And she can still rely on the Lula wow factor; he’s been a constant presence on the campaign trail and his one-man show is one of the main factors saving her.

Over in Uruguay, one era guaranteed to end is the presidency of José Mujica – known as Pepe – the opulence-shunning farmer-cum-head of state who is happiest driving his battered Volkswagen Beetle around his estancia. He remains one of the most popular presidents in South America having ushered in a range of reforms such as gay marriage, abortion rights and state-regularised marijuana sales that have made the country the most liberal in the region. Mujica cannot run again and his chosen successor, 74-year-old ex-president Tabaré Vázquez, is by no means guaranteed victory. He is struggling to pull away from the more youthful National party candidate Luis Lacalle Pou.

The pink tide may not be drying up – and October’s votes probably won’t upset the applecart – yet leftist leaders can’t allow their buoyant economies to do the talking anymore as growth slows throughout the region. “In the first decade of the pink tide there was an uptake in commodity prices and leaders were handed a gift,” says Sabatini. “And I think, right now, this will tell us who is best prepared to deal with the downturn.”

Chávez has gone and the constant calls for “solidarity” are beginning to ring hollow. South America has an opportunity to turn its soundbite cohesion into real political and economic gains that help the region and aid the millions that continue to live in poverty. The next mandates will be a litmus test for the pink tide and its enduring relevance.

Zipping through São Paulo from east to west at second-storey height, the city’s Elevado Presidente Costa e Silva expressway was built more than 40 years ago when a city planner hoped to relieve traffic congestion by erecting a flyover on top of stately Avenida São João. Dubbed the Minhocão – or “giant worm”– it quickly became an eyesore and has been the subject of demolition plans by almost every city mayor since its construction. But now, with the expressway’s deactivation finally in sight as one of the provisions of São Paulo’s new strategic master plan, controversy has stirred anew over what is to become of it.

The road is closed to traffic each night from 21.30 to 06.30 and on Sundays when residents turn out to walk, jog, cycle or just relax on the car-free asphalt. These Sundays have encouraged campaigners to call for its preservation – and conversion into an urban park.

Advocates for demolition point out that some of the Minhocão’s worst attributes are to be found underneath it at street level. This is where the flyover’s looming, grimy bulk slices neighbourhoods down the middle and where concentrated traffic fumes blight the façades of a fine stock of art deco buildings – dirty and dilapidated but still standing.

California’s Democrat governor Jerry Brown has made a point of riding and flying with his constituents. When travelling by air he usually flies commercially and in economy both inside and outside the state. One of the first official flights he took during his third term as governor was with Southwest Airlines from Sacramento to Burbank. The lack of an entourage was obvious when he was said to have walked off the flight carrying his own garment bag.

Were Brown a first-term governor his transport austerity might be viewed as being just a bit of showmanship in the face of California’s budget shortfalls. But many say it’s his personality. “Brown is, by temperament, a loner,” says University of Southern California history professor Kevin Starr. “As governor of a state recovering from a near-fatal financial disaster, moreover, he likes to set a good example. So he rides in an unpretentious car driven by his wife or a California Highway Patrol officer.”

His take on personal transport carries over from his first two terms as governor in the 1970s and early 1980s, when he was regularly seen in a blue base-model 1974 Plymouth Satellite. At the time he refused to ride in the official limousine that then-predecessor governor Ronald Reagan had used.

It seems that Brown and those responsible for getting him to and from the state-capitol building are sometimes at odds regarding how he gets around. “Brown still walks to a lot of things,” says David Siders, political reporter for The Sacramento Bee. “He’ll often walk down the sidewalk, sometimes frustrating his security.”

Given his unflashy style it makes sense that the man prefers to lay low and in transit with the masses. Brown, a former Jesuit and student of Buddhism, has devoted himself to progressive politics. He champions electric cars and has directed $1.4bn (€1.1bn) to the state’s much-delayed high-speed rail project.

Brown’s predecessor Arnold Schwarzenegger, while an advocate for cleaner cars and high-speed rail, was often seen driving suvs and taking intrastate trips on his private jet. This surely turned heads, yet his successor seems to have left much of that pomp in the car park. We’ll see if his low profile pays off come November’s election, when Brown seeks a fourth term.