By Lori Turnbull

April 8, 2026

Of all the floor-crossers who’ve inched Prime Minister Mark Carney closer to a majority in the past six months, Marilyn Gladu won the award Wednesday for generating the most spit-takes.

Just in time to attend the Liberal Party National Convention in Montreal this weekend, Gladu — a very Conservative member of Parliament since 2015 — announced that she had defected to the Liberal caucus, to collective shock across the Ottawa bubble.

Gladu is the fifth MP, and the fourth Conservative, to do so since Prime Minister Mark Carney became leader just over a year ago. But this one is not like the others – and the adjustment may prove a bridge too far for Gladu, for some members of the Liberal caucus, and, ultimately for Carney.

As the others did before her, Gladu cited Carney himself as the primary reason for the change in affiliation. In a public statement, she referred to Carney’s “serious leadership,” his “constructive, collaborative approach,” and a “real plan to build a stronger and more independent Canadian economy.”

That’s all well and good. There’s no doubt that the Liberal-bound traffic is due largely to Prime Minister Carney, his personal popularity, and his unique suitability to meet the current economically perilous moment.

Further, Mr. Carney’s focus on economic growth, security, and sovereignty is an easy message to get behind and it’s unifying enough to transcend traditional party boundaries, particularly in the current global context.

MPs Chris d’Entremont, Michael Ma, and Matt Jeneroux, all recruited from the Conservative caucus to the Liberals before Ms. Gladu was, could be described as moderate conservatives, which makes their decision to join Mr. Carney more obvious and logical.

If we still had a Progressive Conservative Party at the federal level, one could imagine them all being part of it.

But let’s be real: Marilyn Gladu is not a moderate conservative, a Red Tory, or anything else that would make her migration to the Liberals a logical step. Some of her constituents have already gone public with their shock at her decision.

Ms. Gladu opposed the legalization of cannabis as well as legislation proposing a ban on conversation therapy, even while the political parties were building a consensus on the issue. She tried to be the leader of the Conservative Party in 2020 but was disqualified.

Let’s be real: Marilyn Gladu is not a moderate conservative, a Red Tory, or anything else that would make her migration to the Liberals a logical step.

Her presence in the Liberal caucus could be much more difficult to broker than d’Entremont’s, Jeneroux’s, or Ma’s, given her staunch opposition to several measures taken by the Liberal government over the past 10 years. It also begs the question: what about her values? Why would she want to join this party anyway?

It cannot be taken for granted that Ms. Gladu will receive a warm welcome from the Liberal caucus, particularly when the cameras aren’t watching. Sure, she brings them one seat closer to a majority. But they’re going to get there anyway with the by-elections taking place on Monday, two of which are safe Liberal seats.

Are we at the point of pure transactionalism in Canadian politics? Are MPs just a vote?

It’s possible that Gladu is tired of the Conservative leadership and looking for a new political home. She would not be the first or only one to conclude that Conservative leader Pierre Poilievre does not offer what she’s looking for — especially if she’s looking for someone who won’t be a drag on her chances in the next federal election, with the Toronto Star reporting today that up to 40 Tory MPs are wrestling with that very fear.

Poilievre, long accused of polarizing rhetoric that drives away at least as many voters as it attracts, has changed his tune recently, pitching a more conciliatory message and opening the door to working collaboratively with Prime Minister Carney on matters facing the country.

But that does not seem to have stopped the bleeding, and it might be too little, too late. Following Ms. Gladu’s departure, Mr. d’Entremont told CTV that there are “still some people that are upset” in the Conservative caucus, which suggests that even more floor-crossings could be coming.

MPs who decide to switch parties are always motivated by at least some degree of self-preservation, but the decision is easier to justify when there are clear principles at play. If the MP in question can build an argument that, based on values, they can no longer sit with the party they were elected to represent, or that they feel more closely aligned with another party, they can continue to make a plausible claim to be acting in the public interest.

But there’s no nobility in musical chairs. Switching parties entirely because of opportunism, despite having emphatically denounced the government and its agenda, looks mercenary. And it’s taking voters for granted.

Prime Minister Carney will ultimately be the one responsible for ensuring Ms. Gladu’s smooth transition. There’s nothing legally or constitutionally wrong with moving from a minority to a majority government through floor-crossings and by-elections.

But it’s a political challenge in the sense that Mr. Carney, as leader, will need to keep the ever-growing caucus together.

That doesn’t mean they need to agree on everything. But they should certainly stand for something.

Dr. Lori Turnbull is a professor in the Faculty of Management at Dalhousie University.