It was all going so well for president Cristina Fernández de Kirchner when she assumed power in 2007: high approval ratings and a buoyant economy allowed the Argentine leader to pursue a hybrid of socially progressive and populist policies. Eyeing the end of her second term in 2015, the scenario has radically altered as South America’s third economy battles high inflation and a US-court-provoked default.

1. Economy
   Argentina has been flirting with recession this year. It experienced negative growth in the first quarter of 2014 but this was promptly rebutted by second-quarter figures from national statistics body Indec showing 0.9 per cent expansion. Perhaps the biggest problem is the government’s trigger-happy money printing, helping to provoke an inflation rate estimated by some private economists to be as high as 40 per cent. The causes and effects of this need to be solved quickly.

2. International relations
   Argentina badly needs a big-name international benefactor. The Falklands/Malvinas debacle makes the UK an improbable bedfellow and the ongoing dispute with hold-out investors (known as vulture funds) claiming money owed from the country’s 2001/2002 crash sent the country into another default. President Obama could have stopped a group of millionaire hedge-fund owners from the US bringing a g20 country to its knees but he chose not to. Who to turn to? Russia is increasingly isolated, meaning that Argentina could sidle up to China, already an important investor in the region.

3. Power vacuum
   She splits opinion but Fernández de Kirchner is an energetic leader who has mobilised a young grassroots powerbase. The country heads to the polls in October and la presidenta isn’t eligible for re-election. With no heir apparent there is likely to be a vacuum. And while the sort of radical, violent polarisation that Venezuela has experienced since Hugo Chávez’s death is unlikely, there are uncertain political times ahead.

Given its history as a hub for oil and the conservative politics that are typically associated with the fossil fuel industry, you could be excused for overlooking Houston’s budding green and liberal city credentials. Yet under the leadership of Annise Parker, a progressive mayor who has made renewable energy a core component of her mayoral strategy, Houston has emerged as a green powerhouse (see issue 70).

But clean energy is just one aspect of Parker’s forward-thinking agenda for Houston. Recently introduced policies on touchy issues such as immigration and homelessness have turned Houston into a model for other American cities. While Parker has remained true to the city’s Texan roots, she has turned Houston into an unexpected bastion of liberalism in a militantly individualistic pocket of the US.

A lot of ambitious Democrats have hinged their 2016 plans on Hillary Clinton’s: if she runs for president, why bother? And then there is Maryland governor Martin O’Malley who is proceeding as if Clinton doesn’t exist.

The 51-year-old – who as mayor of Baltimore was one of the inspirations for The Wire’s slick up-and-comer Tommy Carcetti – contains a mix of the old Democratic party (he is a big-city Irish politician) and new (he has been more progressive than Barack Obama on immigration and same-sex marriage).

In January, O’Malley’s second term as governor ends and he is likely to throw himself into a presidential campaign full time. The question remains, though: what are his motives? Does he think he can beat Clinton or is he aiming to become her running mate or successor?

1. Canada
   Justin Trudeau, leader of the opposition Liberals, is favourite to oust prime minister Stephen Harper, despite the best efforts of the left-wing New Democratic Party to turn the contest into a three-party race. Given how badly the Liberals fared last time around under Michael Ignatieff (they came third) it would be a remarkable turnaround.

2.
Chicago
Barack Obama’s former chief of staff Rahm Emanuel is running for re-election as city mayor but his approval ratings are dangerously low. A high crime rate and rows over education have damaged his standing. His Democratic rivals will attack him from the left, particularly head of the teachers’ union Karen Lewis.

3.
Guatemala
President Otto Pérez Molina cannot stand again as the constitution limits the head of state to a single four-year term. This has led to an odd quirk: the previous poll’s runner-up has won second time around in every election since 1995.

Guaymas will be home to the second-biggest port in Mexico following a large investment that will double its capacity to more than 30 million tonnes a year. It is hoped the port will boost connections with Arizona.