It's astounding how much the political landscape has shifted in the 18 months since the Parti Québécois took power in September 2012.

In the last campaign, over 34 steamy, sweltering days in August and early September, the election was fought to the rhythm of pots and pans banging in the streets, and a seemingly unanimous public call for a crack down on endemic corruption and collusion in the awarding of public works contracts.

This time, students are contentedly completing their semesters. The Charbonneau commission is well into its probe of alleged wrongdoing in the construction industry.

Last time, then-premier Jean Charest's back was up against a wall, his popularity uncomfortably low, with a broad public feeling of Liberal fatigue after nine years in power.

This time, the public has had a chance to kick the tires of Pauline Marois's slim minority government, without yet having grown weary of it.

And, despite not scoring much in the way of great achievements thus far, she has also managed to avoid tripping up too badly.

The grand plan and the charter

Of course, there is also the centrepiece of the Parti Québécois plan: the proposed secular charter of Quebec values.

When the charter was first unveiled, the ultimate political gain for the PQ was unclear.

It was a highly divisive document calling for unprecedented restrictions when it comes to freedom of religious expression. How could such a thing ever work to rally fresh support?

But then, the plan began to work.

And the reasons why became clear.

At first, the Liberals did exactly what you would expect: they unconditionally opposed the charter.

But soon, tensions grew within the caucus.

Those tensions were coming from MNAs who were quickly finding out many of their constituents actually kind of like the idea behind the charter.

So the position softened, making leader Philippe Couillard appear soft and indecisive.

Marois's plan was working. The PQ's poll numbers went up, while the Liberal luster was tarnished.

Timing is key

But, as the Action Démocratique du Québec's Mario Dumont learned in 2007, timing is everything.

Back then, by the time the election came around, Dumont's surging popularity, furled by the public debate over accommodations for cultural minorities, was already wearing off.

Marois doesn't want to make the same mistake with the popularity she has amassed over the charter.

All of which leaves the opposition parties in a challenging spot.

On the one hand, underscoring the divisive, controversial aspects of the charter could backfire, since polls suggest more than half of Quebecers like the idea.

On the other hand, if the Liberals and the Coalition Avenir Québec focus their campaigns on jobs and the economy, they risk helping to build the impression that the PQ has in fact made a number of important industrial announcements in vote-rich regions outside Montreal.

Put all that together, and it's no wonder premier Marois believes there is no better time to call an election than right now.