Traitor, shameful, brave, principled.
There are a variety of terms used to describe MPs crossing the floor. But history shows us that there is one word that does not always stick when Canadian politicians change one party affiliation for another: re-electable.
Jaws dropped in Ottawa following the revelation that Conservative veteran Chris d’Entremont will join the federal Liberal caucus, with Premier Mark Carney hinting that others could follow.
Land crossing is a political phenomenon that dates back to the Confederacy. But a dive into the record books shows that it has increasingly come at an electoral price.
“Switching parties is an extremely risky move that almost always hurts a politician’s re-election chances,” said Semra Sevi, an assistant professor in the political science department at the University of Toronto.
It tracked all MPs who switched Confederation parties until 2015. The paper found that until the mid-20th century, crossovers received almost the same percentage of votes in elections immediately after switching parties as the previous one.
But since the 1970s, their fortunes have declined, he said.
“As parties become institutionalized, the electoral cost of change has increased dramatically. That makes political survival outside one’s own party increasingly unlikely,” Sevi said.
“There are rare cases of success. So time will tell if this will be one of them.”
Over the years, hundreds of MPs have changed affiliation: some sit as independents or found their own party, while some of the most memorable cases involve joining their former rivals.
Switches labeled ‘opportunistic’
Sevi said a congressman’s chances of being re-elected after switching parties often depend on whether voters believe his reasons.
D’Entremont said he no longer felt represented in conservative leader Pierre Poilievre’s party and noted his “negative” approach to politics.
“Change is often seen as opportunistic, so it damages credibility,” Sevi said.
“This is a change that is happening about seven months after the election was held. So it really depends on whether the voters in your constituency agree or not.” [with] their reasons.”
On Tuesday, the Acadie-Annapolis MP confirmed he left the Conservative caucus to join the ruling Liberals. Taryn Grant has the story.
As a more progressive conservative, d’Entremont could sell his decision to Acadie-Annapolis voters without pushback at the polls. The riding, formerly West Nova, has voted red and blue over the years. D’Entremont won re-election in April by just 533 votes.
While there may be political consequences (and insults) for changing party affiliation, there is nothing stopping it.
there has been failed attempts to force a cross-party MP to seek re-election under the party’s new banner through a by-election, but those bills failed to become law.
Notable floor crossings through the years
Jenica Atwin became the first Green MP elected outside of British Columbia during the 2019 election and helped grow the party’s presence in the House.
Two years later, he went on to sit with Justin Trudeau’s Liberals, pointing to party infighting, including over issues like the Israeli-Palestinian conflict. Contrary to the trend, she was re-elected as a Liberal that same year. Atwin did not run again in this year’s general election.
In 2018, Leona Alleslev left the Liberals to join the opposition benches, condemning Trudeau’s leadership. She was re-elected the following year, but was defeated in the 2021 election.
The move gives Andrew Scheer a bilingual MP from a Toronto suburb who will be key to him winning the next election.
Eve Adams left the Conservative government to join the Liberal Party in early 2015, citing “petty leadership” as the reason. Adams’s time as a liberal was relatively short-lived. He ultimately lost the Liberal nomination to run in the 2015 election against Marco Mendicino.
The early 2000s saw a series of defections, including a mass exodus from the Canadian Alliance led by Stockwell Day. MPs were increasingly dissatisfied with Day’s leadership and the party’s disappointing election results.

Over the course of a few months, 13 of the party’s 66 deputies left the right-wing party or were suspended. Some eventually rejoined while others formed the Democratic Representative Caucus.
The schism eventually led to Day’s resignation and spurred a merger with the Progressive Conservative Party to create the modern Conservative Party.
If d’Entremont wants to return to the House after the next election, he might want to take notes from fellow Nova Scotian Scott Brison, who just days after the right-wing merger crossed the floor to sit with the Liberals. He defended the move, saying he wanted to work with “a party driven by bold ideas, not rigid ideologies.”
Kings-Hants voters returned him to the House election after election, often by wide margins.

Perhaps the most dramatic crossover in Canadian history belongs to Belinda Stronach, who not only joined the Liberals in 2005, a year after running for the Conservative leadership, but ended a relationship in the process.
Stronach had been dating Conservative Peter MacKay for a few months, before shocking the country when she revealed she was joining then Prime Minister Paul Martin’s cabinet. The extra vote allowed his minority government to hold on for a few more months before it was finally defeated.
In an infamous interview, MacKay returned to his father’s farm in Lorne, N.S., and declared that his heart was “a little beat up.”
The Liberals would lose in the 2006 election, but Stronach won re-election in Newmarket-Aurora as a Liberal candidate by a larger margin than as a Conservative.
In those 2006 elections another very controversial change occurred.

Just days after winning the Vancouver-Kingsway race as a Liberal, David Emerson switched parties and joined Stephen Harper’s Conservative cabinet.
Emerson argued that joining the government was the best way to serve his constituents. But the decision sparked a chorus of outrage from liberals who had worked on his campaign and accusations that Harper had offered an “incentive” to Emerson, contrary to the Conflict of Interest Act.
It sparked outrage and triggered an ethics investigation. Both Harper and Emerson were cleared by the ethics commissioner. Emerson did not run in the 2008 election.
