There are just six weeks to go — and two before voting begins — in the Conservative leadership race. Candidates are jostling for position and pushing for the smallest edge. 

There is little indication that anyone is breaking out of the pack.

But this race will be won at the most granular of levels, with individual voters holding potentially outsized sway in deciding who will be the next leader of the party. Candidates would be wise to spend the little time that remains making their pitch in ridings where individual members will carry the most weight.

There has been little movement in the Conservative Leadership Index, a composite of four leadership metrics including fundraising, polls and endorsements, since the last update of March 23.

Maxime Bernier remains at the top of the pack with a score of 19.9, suggesting he would take about 19.9 per cent support on the first ballot if the vote were held today. He is followed closely by Kevin O'Leary at 17.8 points.

Andrew Scheer and Erin O'Toole are also rated in double-digits, at 13.4 and 11.2 points, respectively.

O'Toole has made the largest gain since last month, up 1.3 points in the index. He is up three points in the monthly average of polls conducted by Mainstreet Research for iPolitics, increasing his support to 10 per cent among decided respondents (Conservative donors of at least $200 who say they are eligible to vote) in the last two weeks.

He has also picked up a number of new endorsements, including from four MPs, three former MPs and four provincial legislators.

O'Leary, slipping 0.7 points, has dropped the most in the index. Though he announced a few new endorsements (one MP, one former MP, one Ontario MPP and two senators), he has slipped 1.6 points in the polls. He has scored between 24 and 25 per cent among decided respondents in Mainstreet's polling in the last two weeks. He had previously been as high as 27 per cent.

No other contestants have experienced shifts in their index score greater than 0.2 points. A full breakdown of the 14 candidates' standings in the index can be found at the bottom of this article.

Scheer, Bernier trade endorsements for poll support

After O'Toole, Scheer had the greatest movement in Mainstreet's polling, increasing his support to 14 to 15 per cent among decided respondents over the last two weeks, and 2.7 points in the index's weighted average. At the beginning of March, Scheer had been in the single-digits.

Bernier has seen a similar drop in the polls, down 2.6 points. The latest two Mainstreet surveys have had the Quebec MP at 17 or 18 per cent among decided respondents. He had recently been as high as 22 per cent.

But Bernier's losses and Scheer's gains in the polls have been counterbalanced by new (and departed) endorsements.

Since the end of March, Scheer has lost three endorsements to his rivals: one MP to O'Toole, one senator to O'Leary and one Alberta MLA to Bernier.

That MLA was one of eight new Alberta endorsements Bernier announced on Tuesday, keeping him in third place in Conservative establishment support behind Scheer and O'Toole.

Also of note was Lisa Raitt's endorsement from former Yukon premier Darrell Pasloski.

The hunt for low-hanging fruit

Yukon is one of the ridings in the country that will likely carry a disproportionate weight in the leadership vote. Each of Canada's 338 ridings will be worth 100 points regardless of the number of members it has. This means Yukon, with a population of about 36,000 carries as much weight as Edmonton–Wetaskiwin (pop. 159,000).

And a riding with a dozen or so members will be as important as one with thousands.

We don't know the riding-by-riding breakdown of the Conservative Party's membership. But based on the number of individual contributors who donated $200 or more to the party in 2016, the ridings with the largest membership rolls are likely to be found in Toronto, Calgary, Ottawa, Vancouver, Edmonton and a few rural ridings in Alberta. 

The party received had at least 300 contributors from ridings in these areas.

But there were a large number of ridings that registered very few contributions to the national party's headquarters — 28 had fewer than 10 contributors in 2016.

Most of them (24) were in Quebec, primarily in and around Montreal and in northern and eastern Quebec. The remaining four were in Atlantic Canada.

Time well spent

Ridings with the fewest Conservative contributors (four or less) were Beloeil–Chambly, Bonavista–Burin–Trinity, Repentigny, Gaspésie–Les-Îles-de-la-Madeleine, Montcalm, Marc-Aurèle-Fortin and Labrador.

Together, these seven ridings will carry half the weight of Saskatchewan. These seven ridings registered 18 contributors. Saskatchewan's 14 ridings had 2,404.

Alberta's 34 ridings had 8,362 contributors. In the 34 ridings with the fewest contributors, there were a total of 226 Conservative contributors. 

If those numbers are reflective of how the electoral district associations (EDAs) with the shortest and longest membership lists compare, then a voter in one of the 34 smallest EDAs could be worth more than 30 times a Conservative party member in Alberta.

And that means a Conservative leadership contestant's time spent among the members of these smaller EDAs is 30 times more valuable than a trip to the Rocky Mountains.

So Gaspé and Labrador City are lovely this time of year — if you're running to be the next leader of the Conservative Party.

Conservative Leadership Index Apr 13

The index is based on four different metrics: endorsements, fundraising, contributors and polls. In tests on 14 recent federal and provincial leadership races in which all party members could vote, the index has replicated the first ballot results with a median error of +/- 2.2 points per candidate.

A more detailed explanation of the index's methodology can be found here.

*As Kevin O'Leary entered the race after the end of the last fundraising reporting period, the index substitutes his poll support in place of his fundraising and contributors. Each candidate's average is then adjusted so that the index adds up to 100.

With files from David McKie