The recent defection of longtime Conservative MP Marilyn Gladu to Prime Minister Mark Carney’s Liberal caucus — followed swiftly by a string of federal byelection wins that secured a governing majority — has reignited a familiar debate in Canadian politics: the merits and risks of “big tent” political parties.

Gladu’s decision to join the Liberal caucus stunned political Ottawa earlier this month, for it was the most dramatic floor crossing in more than 20 years, when former high-profile Conservative MP Belinda Stronach jolted to Paul Martin’s Liberal caucus in 2005, saving his then minority government from imminent defeat in the House of Commons.

Gladu’s defection is remarkable not merely because it helped Carney’s Liberals secure a coveted majority government, but also because it was least expected. The veteran Conservative MP built a reputation in Ottawa over the past decade as a prominent social conservative who expressed opposition to abortion, vaccine skepticism and support for the trucker convoy — she even initially opposed a bill banning the harmful practice of conversion therapy. 

But Gladu’s defection didn’t come in isolation; the Sarnia—Lambton—Bkejwanong MP followed in the footsteps of four other opposition MPs; three from the Conservative Party one from the NDP. And this is emblematic of a deeper shift underway in Mark Carney’s Ottawa: one that signals a return to a style of governance that had largely disappeared over the past two decades. Lost in much of the commentary is a simple but important truth: big-tent politics was once the norm in Canada — not the exception. 

Spanning the 20th century through to the mid-2000s, Canada’s most successful federal governments were defined by broad, ideologically diverse coalitions. The Progressive Conservative government under Brian Mulroney and the Liberal governments of Jean Chrétien and Paul Martin governed from expansive political centres that accommodated a wide range of views, from left-wing to right-wing and everything in between.

Mulroney’s coalition included not only economic conservatives and Quebec nationalists, but also pro-labour voices and socially progressive MPs — particularly from Ontario and Quebec. Similarly, the Chrétien-Martin caucus was hardly ideologically monolithic. It included dozens of socially conservative MPs, fiscal hawks and ministers who held traditionally small-c conservative positions on defence and foreign policy. These were brokerage governments at their best: they weren’t defined by rigid orthodoxy, but by their ability to hold together competing perspectives brokering differing sentiments across the country. 

But that big tent model of politics and governing began to shift in 2006.

Under Stephen Harper, and later Justin Trudeau, Canadian federal politics became more tightly managed, more disciplined and arguably more ideologically constrained. Caucus cohesion and strict discipline were prioritized over genuine debate on contentious issues. Independent-minded MPs became rarer as policy debates in the Liberal caucus were monitored by Prime Minister’s Office staff, making MPs less comfortable expressing views that might go against the party leadership.

What appears to be emerging under Carney’s leadership is arguably a departure from this recent tradition and a return to an earlier era of big-tent politics as practiced under the Mulroney and Chretien-Martin governments. 

Carney’s caucus is beginning to resemble a genuinely broad coalition attracting figures from across the political spectrum. The juxtaposition is striking: Marilyn Gladu, a social conservative with anti-establishment credentials, now sits alongside former New Democrat Lori Idlout within the same caucus. And yet, they coexist within Carney’s Liberal Party. 

The defining feature of big-tent politics isn’t unanimity, but managed disagreement. It’s the recognition that a country as regionally, culturally and economically diverse as Canada cannot be easily represented by ideologically uniform parties. Instead, it requires broad-based brokerage parties that can absorb and reflect that diversity — even when it produces tension within a government caucus. 

Big-tent parties and governments face challenges too: they can struggle with internal coherence and blur policy direction, thereby complicating decision-making. Managing a caucus with wide-ranging views can also be very challenging and requires a different kind of political leadership — one that prioritizes consensus-building over command-and-control tactics. 

But on balance, big-tent governments mirror the country they serve — in this case, the diverse federation that is Canada. They create space for competing ideas to be debated internally rather than across hardened partisan lines. They reduce the reliance on ideological purity tests that can alienate independent voices and limit a party’s ability to evolve. And they acknowledge the fundamental reality that most Canadians don’t fit neatly into rigid political categories.

In that sense, the re-emergence of big tent politics under Carney’s leadership may be less a partisan development than a democratic one. The early days of the Carney era suggest that this approach is being tested in real time. Whether the return of big-tent politics under Carney is sustainable, and whether it delivers better policy outcomes for Canada, remains to be seen.

What is clear, however, is that Canadian politics has entered a new phase under this prime minister. Or perhaps more accurately, it has rediscovered an old one. And in a country as complex as Canada, that may be exactly what is needed.

Andrew Perez is a non-profit leader, public affairs strategist and Liberal Party commentator.

© National Observer