Tuesday's news that NDP Member of Parliament Lori Idlout had crossed the floor to the Liberals seems to be yet another piece in the majority puzzle for Prime Minister Mark Carney, but what could that majority actually look like?Idlout's crossing is the fourth instance of MP defection from a rival party to the Liberals since Carney's premiership began and the first to come from the NDP, with the three previous crossings coming from the Conservatives.The Nunavut MP's defection means that the Liberals currently have 170 seats in the House, meaning they need just two more seats to make it to the 172-seat majority threshold.At this number the Liberal would only have to win two of the three upcoming by-elections, which are due to occur in April.By-elections will take place in the ridings of University-Rosedale and Scarborough Southwest, both in the Greater Toronto Area, and in Terrebonne, near Montreal.The two GTA-based ridings were both won in overwhelming Liberal victories in the 2025 federal election, with over 60% Liberal support in both, but Terrebonne was forced into a by-election because of an annulment by the Supreme Court due to the Liberal candidate winning by a single vote.This floor-crossing means that now the Liberals only need to win two of the three by-elections to get their much-coveted majority, and looking at the results in the two GTA ridings, it seems like that is a foregone conclusion..However, this potential slim majority may prove to give Carney more headaches than relief.Having such a slim majority means that he will be expected to govern the country like a majority-wielding PM but will be hard pressed to keep his caucus in line to vote together.From an optics perspective, it may be easier for the prime minister to govern with his current strong minority, as he can still blame the opposition for any perceived lack of movement on policy.With a majority of only one or two seats, government whips will be run off their feet to make sure that every MP stays aligned to government positions when voting.With some Trudeau-era MP's, like former Environment Minister Steven Guilbeault, who had resigned from cabinet over disagreements with Carney's decision to support an MOU between Alberta and the federal government, uniform support from MP's may not come so easy. .If this growing, more centrist, post-Trudeau Liberal Party hopes that its current growth will continue, it may find that playing the coalition game may not work for extended periods of time, especially in such a volatile and ever-changing world.This is not to say that the Liberals won't be hoping for a majority; any party dreams of one. This is just to say that governing a party now containing Liberals, as well as former Conservatives and NDPers, will be no easy feat.Keeping this patchwork coalition together will be the first major test of party management that the prime minister will have had since entering politics.Despite this, Mark Carney will be hoping that this trickle of floor-crossers and potential by-election wins will elevate his party to further stability in the House, but with a majority, he will forfeit some of the leeway he currently has when it comes to getting policy passed.A majority, regardless of how small, is expected to be much more efficient than a minority, regardless of how big.That is the issue the Prime Minister will likely soon be facing.
