A wise man (OK, it might have been Homer Simpson) once said that "people can come up with statistics to prove anything ... forfty per cent of all people know that."

Two duelling poll-backed narratives have taken hold in the Canadian political commentary in recent weeks as the country heads into an election year.

The first narrative runs something like this:

The shine has come off Prime Minister Justin Trudeau as the 2019 federal election approaches, but his Liberals remain the favourites to win re-election. The margin between the Liberals and Conservatives is relatively narrow — perhaps two to five percentage points — but his party holds leads where it counts in the battle for seats, particularly in Quebec. Boosting Trudeau's chances is the fact that he retains a wide, double-digit advantage over Conservative Leader Andrew Scheer on who Canadians prefer as their prime minister. That personal edge could prove decisive.

The second narrative looks a little like this:

Trudeau's popularity is collapsing at the least opportune moment for his party, with just 10 months to go before the next federal election. His approval ratings are plummeting and Scheer has surpassed the beleaguered prime minister as the man more Canadians want to see leading the country. The Conservatives are ahead on the question of which party people think would do a better job of governing Canada — including in Quebec — and Scheer is seen as the better person to handle a myriad of issues that could turn out to be next year's ballot box question.

The numbers exist to back up both of these narratives.

Canadians might be forgiven if the polls have confused them over the last few weeks. Forum Research put out a survey showing the Conservatives ahead by nine points. Nanos Research, which reports the results of its four-week rolling surveys weekly, showed significant shifts, with a six-point Liberal lead turning into a one-point Conservative edge and then back into a two-point Liberal advantage.

Campaign Research put the Tories up by two and then Ipsos/Global News put the Liberals ahead by five. The Angus Reid Institute (ARI) did not release voting intention numbers, but put Scheer ahead of Trudeau on Canadians' choice for prime minister by six points, a day after Nanos gave Trudeau the edge by 11 and two days after Campaign put the margin at 10 for Trudeau.

Somehow, all these polls are supposed to be talking about the same country.

Reasons behind differences unclear

The reason for the discrepancies between the polls is hard to figure. Some are easier to dismiss: Forum has had a systemic bias in its polling that has favoured the Conservatives throughout 2018, giving the party a lead of an average of 10 points during the year when all other major pollsters were suggesting an environment that is about 10 to 15 points better for the Liberals.

But the others are more puzzling. Mode of contact is unlikely to be the reason.

Nanos does its polling the old fashioned way, reaching people over the telephone (both land lines and mobile) with live interviewers and achieving a response rate of about nine per cent — about as good as it gets in polling these days, and four to fives times better than the response rate for a standard automated interactive voice response survey like Forum's.

The ARI samples from its online panel — a significant methodological difference — but so does Ipsos and Campaign.

The discrepancies are likely due to the degree to which these panels are representative, how the questions are structured and how the responses are weighted. But it's not clear how these factors are contributing to the spread in the results.

So where do things really stand?

Liberals likely leading more competitive race

The consensus of the polls, taking into account the longer-term trends over the last 12 months, certainly point to a more competitive race between the Liberals and the Conservatives than we saw in 2015, when the Liberals won the popular vote by just under eight points and secured a sizeable majority government.

Considering the normal sampling error, an actual lead of about three points for the Liberals should naturally produce polls showing the variety of results that have been published this week by Nanos, Ipsos and Campaign. While the situation isn't exactly comfortable for the Liberals, the national numbers mask what is a reasonably good electoral map for the party at the regional level.

Conservative Leader Andrew Scheer has seen his personal numbers improve over the year. (Adrian Wyld/Canadian Press)

More polls suggest Trudeau retains a personal lead over Scheer — the prime minister benefits from his incumbency and name recognition advantage. In October, Ipsos found that just 54 per cent of Canadians could name the leader of the Conservative Party of Canada (eight per cent said it was Doug Ford).

The trend lines, however, should worry Trudeau. They might wobble up and down from month to month (Ipsos shows an improvement for the Liberals since October, Nanos shows the opposite) but the landscape has gotten worse for the the prime minister over the course of 2018.

Trudeau, Liberals trending down

Since this time last year, Nanos and Campaign have recorded a drop of five points in Liberal support. Ipsos shows the Liberals steady, but their lead over the Conservatives decreased by two points. Nanos and Campaign also show the Conservatives in a better position, up four and five points, respectively, since November and December 2017.

Trudeau's score on the question of who Canadians want as prime minister has dropped three points according to Campaign and ARI, and nine points according to Nanos, while Scheer's score has improved by between four and 12 points.

That's an average swing of seven points between the Liberals and Conservatives and 13 points between Trudeau and Scheer in the last year.

Pollsters agree that NDP Leader Jagmeet Singh has not made progress in public opinion in 2018. (Adrian Wyld/Canadian Press)

All four pollsters agree that the New Democrats under Jagmeet Singh have also lost ground, down one to three points in voting intentions. Just five to six per cent of Canadians pick Singh as the best person to be prime minister.

That's probably good news for the Liberals, as the party has a better chance of winning elections when the NDP is struggling.

Much can change (and almost certainly will) between now and Oct. 21, when Canadians cast their ballots for real. At this point, there are some warning signs for the Liberals in these polls, hinting at potential trouble ahead over the next 10 months.

But are they in as much trouble as some of the year-end narratives suggest? Probably not. Nevertheless, that's probably not the silver lining the prime minister was wishing for this Christmas.