I think the 5% threshold makes “targetted killing” a lot less viable, but it doesn’t eliminate the possibility altogether. It may still be possible to use a slightly-more-mainstream party in such a way; if a party gets 5% of the vote nationwide but 15% in Trudeau’s district, that’s still a relative vote share of 3, which should be far more than Trudeau achieves. Still, I think the combination of a threshold with a “you don’t actually need to be electing to Parliament to hold a leadership position” rule should be sufficient to reduce the “targetted killed” problem to a tolerable level at least.
The more I think about it though, the more I lean towards something closer to MMP over the 100% single-winner districts approaches. If a party’s best showing in any one district is under 15%, I think it makes the most sense for that party to only have at-large seats; the remaining 85% of that district’s voters will really feel like they drew the short straw otherwise. (Also, I imagine the possibility of losing one’s seat to a third-party candidate with far less support within one’s district would cause a lot of incumbents to oppose such a system.) Still, I think there is considerable middle ground between MMP and your system that allows for having substantially fewer at-large seats (as a fraction of all seats) than you get in Germany or New Zealand, and this middle group could easily be better than MMP.
I confess that I don’t understand the detailed working of Fair Majority Voting either; it’s clear enough in the two-party case, but I’d have to study it in a lot more detail to learn how the algorithm works in general.
Another solution that might be more palatable than allowing someone who just lost their own district to become PM is to normalize having PMs from either of the Houses of Parliament. I’m not sure how Canada elects its senators, but if you make that as province-wide PR then party leaders can be decently assured to get a Senate seat. (Actually, I checked and Senators are appointed by the Governor-General on the advice of the Prime Minister; constitutional convention might make for the leaders of any parties represented in the Commons to be guaranteed a Senate seat).
I think the 5% threshold makes “targetted killing” a lot less viable, but it doesn’t eliminate the possibility altogether. It may still be possible to use a slightly-more-mainstream party in such a way; if a party gets 5% of the vote nationwide but 15% in Trudeau’s district, that’s still a relative vote share of 3, which should be far more than Trudeau achieves. Still, I think the combination of a threshold with a “you don’t actually need to be electing to Parliament to hold a leadership position” rule should be sufficient to reduce the “targetted killed” problem to a tolerable level at least.
The more I think about it though, the more I lean towards something closer to MMP over the 100% single-winner districts approaches. If a party’s best showing in any one district is under 15%, I think it makes the most sense for that party to only have at-large seats; the remaining 85% of that district’s voters will really feel like they drew the short straw otherwise. (Also, I imagine the possibility of losing one’s seat to a third-party candidate with far less support within one’s district would cause a lot of incumbents to oppose such a system.) Still, I think there is considerable middle ground between MMP and your system that allows for having substantially fewer at-large seats (as a fraction of all seats) than you get in Germany or New Zealand, and this middle group could easily be better than MMP.
I confess that I don’t understand the detailed working of Fair Majority Voting either; it’s clear enough in the two-party case, but I’d have to study it in a lot more detail to learn how the algorithm works in general.
Another solution that might be more palatable than allowing someone who just lost their own district to become PM is to normalize having PMs from either of the Houses of Parliament. I’m not sure how Canada elects its senators, but if you make that as province-wide PR then party leaders can be decently assured to get a Senate seat. (Actually, I checked and Senators are appointed by the Governor-General on the advice of the Prime Minister; constitutional convention might make for the leaders of any parties represented in the Commons to be guaranteed a Senate seat).