More than two-thirds of the Conservative caucus has gotten behind one of the 14 candidates for the party's top job. Most are supporting either Erin O'Toole or Andrew Scheer — and O'Toole has now surpassed Scheer as the favourite of Conservatives in the House of Commons, even luring two of Scheer's former backers to his side.

But polls and other metrics suggest Maxime Bernier or Kevin O'Leary are leading the pack. If either of them wins, they could find themselves at the head of a Conservative caucus that overwhelmingly preferred someone else.

In a series of announcements over the last week, O'Toole increased his tally of backers among the 97 Conservative MPs to 26. Scheer, who had previously been the leader among MP endorsements, has 23.

The latest endorsement came from Jim Eglinski, who had initially supported Scheer for the party's leadership when he launched his bid in September. Eglinski is the second MP to switch his support from Scheer to O'Toole. Kelly McCauley did so on March 2.

Jim Eglinski has endorsed Erin O'Toole after initially backing Andrew Scheer. (Adrian Wyld/Canadian Press)

In an interview with CBC News, Eglinski says he is "a lot more in tune with Erin than with Andrew," though he says Scheer is "a very competent person."

"Personally, I had to look where my heart was," said the former RCMP officer, highlighting O'Toole's military service.

Scheer had entered the race a few weeks before O'Toole. Eglinski says that when O'Toole launched his campaign "a whole new playing field opened up for me."

But he says it was just a coincidence he and McCauley have swung from Scheer to O'Toole, rather than necessarily being a sign of a broader movement within caucus.

Do endorsements matter?

"Endorsements in a leadership race are an unofficial early primary," says Chad Rogers, a partner at Crestview Strategy. "They indicate if a candidate is viable and whether they could potentially scale up their support."

Endorsements are not always predictive of the final outcome. Rogers points to the 2015 Ontario Progressive Conservative leadership race, when caucus favourite Christine Elliott lost to Patrick Brown.

But the rules of the Conservative leadership vote will give each of Canada's 338 ridings equal weight, regardless of how many members the riding has, potentially giving the local MP more influence.

"Endorsements only really matter if the people doing the endorsing can deliver votes to the candidate they are supporting," says Tim Powers, vice-chairman at Summa Strategies. "A name is just a name unless it comes with tangible results."

Of the Conservative MPs, 64 have already shown their colours. Another nine MPs are running for the leadership, while five (Interim Leader Rona Ambrose, Deputy Leader Denis Lebel, Chief Opposition Whip Gordon Brown, House Leader Candice Bergen and Diane Finley, a member of the leadership election organization committee) must remain neutral.

That leaves 19 MPs who have yet to back a contender, including former cabinet ministers Rob Nicholson, Pierre Poilievre and Michelle Rempel.

O'Leary, Bernier still lack caucus support

Just six MPs have backed Bernier for the leadership, while O'Leary's list of endorsers from the House is limited to one.

Among the 39 Conservative senators, who are also members of the Conservative caucus, Scheer has nine endorsements, Bernier seven, O'Toole two and O'Leary one.

Steven Blaney has two senators backing him, while Michael Chong and Lisa Raitt each have one. Raitt and Kellie Leitch each have three MP endorsements and Chong has two.

One MP has endorsed O'Leary, left, and six have endorsed Bernier. (Canadian Press)

The successful leadership campaigns of Patrick Brown in Ontario, Christy Clark in British Columbia and Donald Trump in the United States show that it is possible to win without the backing of the party establishment.

But if Bernier or O'Leary prevail, they will need to lead a potentially unfriendly caucus.

"A candidate winning with little or no caucus support will have the challenge of bringing the team together," says former Canadian Alliance leader and Conservative cabinet minister Stockwell Day.

"If the losing candidates get behind the winner enthusiastically and remain that way, the problem can be overcome. If they don't, the new leader will have an uphill battle."

Powers thinks Bernier would have an easier time than O'Leary navigating this issue.

"He has been part of the caucus and knows its dynamics, and that is a potential advantage," says Powers.

"O'Leary has yet to demonstrate he plays well with others or understands the importance of a parliamentary caucus. He could have issues if he fails to manage the ecosystem the right way."