POLITICS

Trudeau's Liberals Must Win Ontario To Have Any Hope Of Ousting Harper (ANALYSIS)

10/07/2015 12:44 EDT | Updated 10/07/2015 12:59 EDT

Although their results vary widely on who is actually in the lead, the polling companies do agree on one thing — the NDP is tumbling. Nanos and Mainstreet, in particular, are at odds in the results they have produced in recent polls.

A series of polls over the past few days have produced a clash of numbers, and Ontario is a key battleground.

In its daily reporting, Nanos has the Liberals on the rise and first overall, by as many as four points. On the other hand, Mainstreet just published a poll with a significant Conservative lead — more than eight points — that would put the Tories close to a majority.

There are other examples of these variations. Leger has the Liberals slightly ahead, as does Innovative. On the other hand, Ekos, Forum and Angus Reid have had the Tories comfortably ahead. Still, only Nanos has the Grits clearly in the lead. Either they are off, or they are the only one getting it right.

What everybody agrees on is the NDP's having fallen to third place and most likely out of contention for victory in this election.

The thing is, national numbers don't mean much. For Justin Trudeau to have even a chance of becoming prime minister on Oct. 19, the one province he absolutely needs to win is Ontario.

He has the Atlantic provinces locked up. In Quebec, he's benefiting slightly from the NDP'S fall, but not necessarily as much as the Bloc and even the Conservatives are.

Contributing to the Liberals' problem in Quebec is the fact that its vote support is too concentrated.

In the Prairies, polling numbers for the Liberals could translate into a couple of gains, especially in Manitoba. Alberta will be, at best, the source of one or two seats while the gains in B.C. will likely be in Vancouver and the close suburbs.

Therefore, in order to actually win more seats than Stephen Harper, Trudeau needs to win in Ontario.

The graph below shows the polls in the province over the past two weeks. As usual, a new Nanos poll is added every three days. Numbers are unadjusted and are as published by each polling firm. The date is the mid-date of when the data were collected.

ontario october 7

As you can see, Ontario has been very stable. Whether the Liberals or Conservatives have the lead is hard to say. Looking only at the polls of last week, it seems the Liberals are slightly ahead.

But unless you only believe Nanos, you can't really argue that the lead is significant.

This is the main reason why Trudeau, despite running what is generally seen as the best campaign, is still a long way from really being able to challenge Harper. For that to happen, he needs to be ahead in Ontario by eight to 10 points. Anything less and it becomes almost impossible for the Liberals to win more seats than the Conservatives.

To illustrate this, let's look at the probability of the Liberals' winning more seats than the Conservatives as a function of the results in Ontario. Specifically, the horizontal axis is the Liberal lead over the Tories in Ontario, in percentage points. This graph assumes the numbers in other provinces don't move much.

liberal party probability

Clearly the Liberals need a lead of at least eight to 10 points to have a chance. The party's odds really pick up around this point. Of course, they can afford a smaller lead if they pick up seats in other provinces. But as we've said, a lot of them are not favourable to the Liberals.

What this graph shows is that unless you believe the Liberals are clearly ahead in Ontario, you shouldn't think Trudeau could become prime minister. As we've seen, for this to be true would require the polls to be currently underestimating the Liberals in Ontario.

There are still two weeks to go before the election. A lot of things can happen. In 2011, after all, Harper's Conservatives weren't in a majority position based on the polls (including the Ontario ones), and we know what happened then.

As long as the Liberals don't poll consistently and comfortably ahead of the Conservatives in Ontario, the overall predictions don't favour them to win or even to make a serious challenge for victory.

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Bryan Breguet has a B.Sc in economics of politics and a M.Sc in economics from the University of Montreal. He founded TooCloseToCall.ca in 2010 where he provides electoral analysis and projections. He has collaborated with the National Post, Journal de Montreal and l'Actualité.

He will provide analysis and updates for The Huffington Post Canada throughout the federal election campaign. For riding by riding projections, visit his interactive simulator.