For Brian Gallant's Liberals, winning the most votes in New Brunswick's Sept. 24 election might not be enough to keep their party in power.

The Liberals have historically won francophone ridings with strong majorities — bumping up the party's popular vote — but ultimately lose or end up with a minority government when the Progressive Conservatives squeak by in anglophone ridings. Whether a party wins a seat by 2,000 votes or 200 votes, they still only get one seat..

It's called an inefficient vote and polls are increasingly suggesting it could be at play in 2018. That means Gallant might need to beat Blaine Higgs' Progressive Conservatives by a significant margin in the provincewide popular vote to secure another majority government.

According to the CBC's New Brunswick Poll Tracker, the Liberals hold a 6.7-point lead over the PCs and are projected to win between 22 and 35 seats, compared to 12-25 seats for the Tories. The most likely outcome would give the Liberals 27 seats, but in three of those ridings the Liberals are projected to have a lead of three points or less. It would not take much to flip those seats blue and drop the Liberals below the 25-seat threshold for a majority government.

The model suggests that if the Liberal lead over the PCs province wide drops below five points, they would no longer be favoured to win more seats than the PCs.

This is nothing new for the Liberals. While their vote's inefficiency is not a constant in every provincial election, the Liberals have needed more votes to win more seats than the PCs in most elections since New Brunswick first adopted single-member districts in 1974.

Ridings won by thin spreads decided 2014 election

This was especially marked in 2014, when the Liberals won just six more seats than the PCs despite taking the popular vote by a margin of 8.1 percentage points. The four ridings the Liberals took by the narrowest margins — the ridings that made the difference between the Liberals and PCs forming a majority government — were won by a difference of 1.4 points or less.

Theoretically, had the popular vote swung toward the PCs by just 1.4 points, those four seats would have gone to the Tories. This means that the PCs could have won a majority government while losing the popular vote by as much as 6.7 points.

While that's the most extreme example, the PCs could still have secured a majority government in 1974, 1987 and 1995 even if they had lost the popular vote by around four points.

On average, the Liberals have needed to win the popular vote by at least 1.7 points in order to win a majority government. If we exclude the 1991 provincial election — in which the Confederation of Regions party formed the official opposition with 21.2 per cent of the vote, splitting the conservative vote with the PCs — the Liberals have needed an average lead of at least 2.3 points over the PCs to win a majority government.

In only three of the last 11 elections in New Brunswick has the PC vote been more inefficient: in 1991, 2003 and 2006.

Francophone vote behind inefficiency

According to the electoral boundaries and representation commission — which redrew the province's electoral boundaries before the 2014 vote — there were 14 ridings in which at least two-thirds of the population listed French as its mother tongue in the 2011 census.

In those 14 ridings, the Liberals won an average of 56 per cent of the vote in 2014, beating the Progressive Conservatives by 28.5 points and winning 13 of them.

By comparison, the PCs won 10 of the 14 ridings with the highest share of anglophones. On average, the PCs were 9.1 points ahead of the Liberals in these 14 ridings. Overall, ridings in which at least four-fifths of the population was English-speaking were won by the PCs by an average margin of 7.5 points.

Liberal gains among francophones in 2014

However, this represents a rather dramatic swing from earlier elections. In 2010, the PCs won those French-speaking ridings by an average of 2.9 points — and the predominantly anglophone ones by a margin of 23 points.

In 2006, there was virtually no linguistic split between the two parties. The Liberals won the most francophone ridings by an average of 0.2 points and lost the anglophone ones by 0.3 points.

It suggests there was a dramatic swing in the francophone vote between 2010 and 2014 that helped the Liberals get elected but increased the inefficiency of their vote. Provincewide, there was a 22.4-point swing in support between the PCs and the Liberals between 2010 and 2014. In francophone ridings, the swing was 31.4 points — twice what it was in English-speaking ridings.

Could Liberal fortunes get worse in 2018?

Two polls published last week suggest the vote could be getting even more inefficient for the Liberals. Forum Research found the Liberals ahead of the PCs among francophones by a margin of 60 to 23 per cent, while a Léger/Acadie-Nouvelle poll put the gap at 64 to 14 per cent. It suggests the Liberals are on track to win predominantly francophone ridings by enormous margins.

But among anglophones, Forum and Léger put the PCs ahead of the Liberals by seven and six points, respectively. They found competitive races or splits that favoured the PCs in Fredericton and Saint John.

New Brunswick Progressive Conservative Leader Blaine Higgs has struggled to make inroads among francophones. (James West/Canadian Press)

If those kinds of numbers are replicated in the Sept. 24 election, the Liberals could win New Brunswick's francophone ridings by an even wider margin than they did in 2014 — giving them few, if any, extra seats in the Legislative Assembly — while losing ridings with higher anglophone populations by narrow margins. This is the recipe for a Liberal popular vote victory that still results in a PC majority government.

The surging popularity of the People's Alliance and Greens further complicates the electoral arithmetic, with the potential to distort the relationship between the popular vote and legislative seats even further.

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