The United States has a major political party that is ideologically cohesive, radical, and firmly committed to its principles. This party is called the Republican Party, or GOP. It is mostly irrelevant to this post whether the ideology makes sense, has been sincerely promulgated, is good for the USA or the world, and so on. It should not surprise you to know that I would answer in the negative, but again, not important. I will also leave out the trivial detail of what that ideological syndrome actually is, except, of course, that we call it “right-wing”.
What has been painfully obvious in the last couple of US elections is that anyone opposed to that agenda and seeks to hinder it immediately at the ballot box has no choice but to form a coalition. We call that coalition the Democratic Party. The name is mostly irrelevant, as the parties have changed positions from time to time. That coalition is not known to be meaningfully “left-wing” in real existing practice, although left-wingers of various stripes are part of it and, of course, some not. It should be known as the Not-Republican Party.
The details of the American electoral system mean that any immediate electoral opposition—-as opposed to non-electoral opposition, which is certainly a real thing, but again not relevant here—-absolutely must win. A full exposition of these details are an interesting technical study in representative politics which I will leave to some other time. However, in the American system, there is never a possibility or threat of a minority government. There is at best legislative and budgetary hindrance of certain kinds. But whoever wins the Presidency holds the official levers until the next election, barring the very high hurdle of impeachment. There aren’t any Confidence Votes.
To the heartfelt disappointment of not a few people, this entirely precludes the possibility of third-party politics. Hindering the Not-Republican Party in pursuit of ideological goals either requires such a sea change in the American political landscape that the Not-Republicans can be safely supplanted by a winning left-wing coalition, or it entails the immediate risk of losing the government. Since there are no minority governments, there is no half-way point.
Losing the government to the Republicans at election N would in theory offer left-wingers an opportunity to build a left-wing coalition ready for election N+1 that could supplant the Not-Republicans. However, the Republicans would not exactly be inert during this period. As they are ideologically opposed to the left, they would act against Not-Republican constituencies to suppress their effect. Third party left-wing movements do not gain serious momentum during Republican right-wing governments. That is because the Not-Republicans become the vehicle of obstruction for (small n) not-Republican constituencies. (Naturally, this whole dynamic is driven by the fact that a very large portion of the US population is on-board with the Republican ideology. Solve that, and this dynamic changes considerably.)
This has the end-result of putting the greatest power in the right-most edge of the Not-Republican coalition. As they are the most ideological sympathetic to the Republicans, they have the power to defect and put power back in the hands of the Republicans. The left in the USA does not have this power, until it effects the aforementioned political sea-change. The practice of the Not-Republicans as hindrance when in opposition and driven by the rightmost Not-Republicans when in power leads to the arguably epiphenomenal effect that the Not-Republicans end up cementing and expanding what Republican ideology sets in motion.
I am laying this out schematically with reference to the results of this recent by-election in Calgary, and in particular claims that the Conservative (Reformatory) Party candidate won due to “vote-splitting” among the opposition. Claims that there is vote-splitting depend on the prior existence of a unified vote. A unified vote for what? A vote to defeat the Reformatory Party candidate.
It’s absolutely clear that the Reformatory Party is the successful importation of a branch of the same ideological syndrome animating the US Republicans. So its role in this drama is clear: a coherent ideological formation of what we call “right-wing”, widely based among the population.
What do we call the coalition to defeat this ideological syndrome? We will, for the sake of discussion, call it the Not-Reformatory party. So claims that the vote is split depend on the existence of a prior Not-Reformatory vote.
The Canadian political system permits the possibility of minority governments, and therefore it is also possible to sustain multiple parties in the legislature. We have 3-4 of them that are “competitive” and are not the Reformatories. The NDP, the Greens, the Bloc (irrelevant for Calgary, obviously), and the Liberals. They exist as separate parties, because they all have at least slightly different agendas, and more than slightly. So our putative Not-Reformatory vote includes all of them. Then if the absolutely priority of Reformatory opponents is to block, and urgently, the Reformatory control of government, the logic of the American system holds over the Canadian one anyway, despite the difference in governmental systems. Which means that the Not-Reformatory coalition party will be driven from its right-most edge (what are now the Liberals). And if the Reformatories must be hindered now, then they must be hindered for as long as possible into the future, until their ideological formation breaks.
So the question is, what level of danger do the Reformatories represent that it justifies the importation of the full American dynamic into Canada, in order to prevent vote-splitting?
UPDATE: I actually mean the question quite earnestly, not rhetorically. It could entirely be the case that Canada has lost the possibility of a political centre that is controllable via the confidence mechanism, and that the Reformatories cannot be unseated by any party currently without that party becoming a coalition of Not-Reformatories (e.g. a fully hollowed-out NDP), and that the Reformatories are so virulent that they must be stopped tomorrow.
In that condition, it is not avoidable that the US political culture must henceforth be adopted.