Senator Alejandro Guillier inside the Chilean congress in Valparaiso, Chile.
According to popular wisdom, if a government's approval ratings are in the low 20s with an election around the corner, odds are that the ruling party will not retain power; people will vote for change.
But popular wisdom is not always right. And this is the hope of the Chilean left.
Just 18 months after winning the 2013 presidential election with 62% of votes, President Michelle Bachelet suffered an unprecedented political breakdown. Public support for both her and her Nueva Mayoría administration - a coalition of the Socialist, Christian Democrat and Communist parties, among others - fell to the low 20s by mid-2015, where it has remained since.
For the November 2017 election, this centre-left coalition had originally set its sights on Ricardo Lagos, a former president who built his political career in the 1980s on courageous, repeated opposition to Augusto Pinochet's dictatorship. And Lagos is willing to run.
But younger progressives are critical of Lagos' 2000-2006 administration, arguing that was more market-oriented than socialist. Despite the 79-year-old's commendable energy, he is polling at 5%.
This situation should favour the prominent conservative ex-president Sebastián Piñera (2010-2014), who is often portrayed as a successful businessman with a Berlusconian twist, to win Chile's 2017 election.
A new hope for the left
But from this unexciting scenario - two former presidents running for president, neither particularly popular - a new name has emerged: journalist and former television news anchorman Alejandro Guillier.
Guiller made his political debut three years ago, winning a senate seat as an independent. He was supported by the Partido Radical, a traditional party that, though its best days are long past, has been a loyal - if almost voiceless - member of the centre-left coalition that has ruled Chile for 23 of the past 27 years.
Now, with Guillier, the Partido Radical has discovered a political goldmine. The newcomer has authoritatively surpassed Lagos in the polls, with support increasing from 1% to 14% in the past six months.
This has made Guillier into an instant cause celebre, and some Socialist congressmen who would be expected to support Lagos have already shifted their attentions his way. So, too, have many government officials who, among other interests, suddenly believe it's possible to keep their posts.
Guillier, the candidate from nowhere, now seems like the only serious competition for Piñera. With recent predictions anticipating a dead heat between the two, he is likely to secure the ruling coalition's nomination to run in November.
Understanding Guillier's rise means understanding Bachelet's fall.
There are two theories to account for her loss of support. Moderate intellectuals have suggested that the Chilean people are simply less socialist than Bachelet and her team thought.
Bachelet's progressive 2013 campaign platform, which absorbed the ambitious demands of a 2011 left-wing students' movement then gaining widespread support, proposed rewriting Chile's constitution and establishing free university tuition, among other goals.
But it's possible that Chileans were, in fact, not quite done with neoliberalism, which the country has largely embraced since the Pinochet years. In this hypothesis, the Bachelet government's plight can be explained away as an inaccurate political diagnosis.
A second theory faults Michelle Bachelet's own thundering loss of political capital for her government's demise. To these commentators, the president's personal popularity - not her reform agenda - was the one and only reason she won the 2013 election.
If, as this argument goes, most people respond more to a candidate than to their platform, then the Nueva Mayoría coalition's political failure correlates to Bachelet's fall from grace, which began when her eldest son and his wife were implicated in suspicious real estate dealings in early 2015.
The perception that a Bachelet family member used his relationships for profit was hard to square with the president's discourse countering abuse and inequality.
Bachelet herself is accused of no wrongdoing. But, in Latin America today, the mere hint of corruption is damning because it resonates with other scandals across the region.
Placing blame on the shoulders of leaders allows progressives in Chile to avoid facing the awkward hypothesis that Chileans may endorse crucial aspects of a market economy.
This hypothesis also comforts progressives struggling to account for the sorry end of the 2000s-era "pink tide" - the rise of leftist leaders across the continent, from Lula in Brazil to Cristina Fernández de Kirchner in Argentina and Hugo Chávez in Venezuela. The Latin American left once seemed unstoppable, but recently corruption and discontent in many countries has fuelled a backlash.
In Brazil in 2016, a conservative wing of congress impeached the left-wing president Dilma Rousseff, Lula's chosen successor. The ouster was pursued on constitutionally shaky grounds, but leveraging a simmering Brazilian case of corruption gave the opposition the power that neither ideological debate nor electoral process could.
Moral suspicions also led Argentina to vote out Kirchner in 2016, and deepened the profound crisis gripping Venezuela after two decades of Hugo Chávez's "updated" socialism (though corruption is far from the only reason Venezuela is failing).
And the left will rise again?
Back in Chile, Guillier has said he will stand for many of the same ideals as Bachelet, adding that, political resistance aside, her reforms are much needed. He has also promoted a state-run economic growth strategy.
Guillier's narrative aims to preserve the social-democratic spirit, but with a bright new face - uncontaminated by corruption, almost without a past.
Accordingly, Guillier sells himself not as a politician but as a grassroots guy. Besides, it's hard to be more credible than the man who delivers the nation's news every night.
Critics highlight Guillier's populist traits (attacking politicians in bulk, endorsing any claim that happens to be fashionable) and his lack of an inner-circle of intellectuals and policy advisers.
But for now, Guillier's autonomy and somewhat ambiguous opinions are working for him. And, of course, being anti-establishment has been winning voters across the world.
If Guillier wins, political thinking in Chile won't change much, but the interpreter will be new. And, for the ailing Latin American left, that might be good enough.