so, when you have a two party system what you see in observation is a pendulum-like effect, where both parties kind of shuffle around a shifting centre that fluctuates like a centre of gravity, through a moving field. it's an entangled system; it moves together, and it morphs, but it just pulls back and forth. so, ideas end up overwriting each other as the pendulum moves back and forth within a kind of closed, broken system.
this wasn't the intent surrounding the construction of the two party system. it was proposed that a two party system would allow for a vigorous debate of opposing ideas, followed by decisive action, as an executive power could be maintained. it was seen as a useful middle point between authority and democracy. yet, because it's nature is cyclical, as it operates like a pendulum, it has simply held the status quo in place, as the whole political architecture reduces to a series of two-person games with predictable outcomes. the two party system is really a hindrance to any movement at all, in any direction whatsoever, and a formula for exactly the kind of gridlock you see in the system right now. nobody can do anything because nothing will last more than a cycle, anyways.
perhaps the problem is in fundamentally misunderstanding how decisions are made collectively. if this system was meant to ensure some balance between authority and democracy, it seems to have fallen too far on the side of authority, and in the process just created a conflict with democracy. for, that is not how decisions are made collectively - we don't convince each other that one idea is superior and rally around it, we need to find common ground and work out compromises. so, perhaps the system is suffering from a serious design flaw, with this two-party hegemony.
when you have a three party system, on the other hand, you don't get that kind of pendulum motion, where the center floats back and forth and re-emerges in the ruling party, continually sputtering all motion in place. rather, you can allow for two fundamentally opposition-style parties - a thesis on the left and an anti-thesis on the right - to introduce ideas from complete opposite sides of the spectrum, with the intent for them to synthesize in the party of the centre, which becomes a ruling party. while the opposition parties may form government from time to time, they do so as opposition parties, and such a rare occurrence signifies a collapse of the centre and construction of a new one. even in a stable three party system, the centre will need to collapse and reform every few decades; that's healthy for democratic renewal, and it ensures that an exchange of ideas is actually happening. when parties stay in power too long, they will stagnate; it's a necessary process.
so, the way debate happens in a three party system is that ideas are introduced on the fringe and sort of linger there for a while, either building support or dissipating out. eventually, if enough support builds on the fringe, motions are introduced that will be supported by one opposition party or the other - and vigorously opposed by the other. so, you end up with a much more direct debate around the value of any issue, because you have proponents of opposite ideologies hashing it out. in canada, this has looked like the ndp getting into debates with the conservatives over free trade, for example - something that found an eventual synthesis in the ruling party, albeit after a rightward shift to the centre brought in by the harper government. in the united states, this might look like the tea party republican faction getting into a debate with the progressive house caucus and really hammering away at issues from their respective positions.
as the government (either the ruling party in the house of commons, or the house or senate majorities) will of course oversee all of this, it has the opportunity to analyze it and try to work it through. and, see, that provides it with a very specific role - to synthesize a position from the thesis and antithesis positions that eliminates the contradictions and results in stable, longlasting policy that actually solves problems and puts sustainable systems in place to solve future ones. it would be useful if it understood that role in those terms. in canada, the ruling liberals have sort of accidentally stumbled upon that by trying to set up expert committees on everything, and delegating a lot of responsibility to the civil service. that is, the way that the liberals govern and have governed for a long time now works huge amounts of wonkish analysis into any decision being made. it's not a purposeful application of dialectics, but it's about as good of one as you could hope a government to stumble onto by accident.
and, that's the real answer as to why canada has all of these nice, shiny things; we avoided a two party system, and allowed for a broader exchange of ideas as a result of it. it's not specifically because of any one party, and in fact even the conservatives had a role to play in developing our universal health care system. rather, it was the ability to present the full spectrum of debate, between a left and a right, that eventually led to the ruling liberals deciding on the socialist nhs as a model to build a single-payer system around, due to heavy pressure by the awkwardly pseudo-left prairie gospel ndp.
so, the debate around forcing a vote on healthcare is about whether it will pass or not, but the fact that that's what the debate is about is exactly why systemic democratic change is impossible in america. you have to have a debate before you can win it! trying to externalize all of the actual democracy into back channel negotiating (and that's actually what aoc is advocating for) just throws it into the firepit. have the debate, yell it out, and come to some understanding about it; it's only as a process of these debates that a workable dialectic can arise. failing should be welcomed, for now.
but, you'll never hear that from aoc or any other politician affiliated with the democratic party because the logic of the two party system annihilates any potential of actual democracy. you've heard her say it - it would be "career suicide". and, she's right. but, if she was in a third party, she wouldn't be concerned about her future cushy career in the democratic establishment, and it wouldn't be a check on her behaviour. so, debate gets stamped out, thesis are not being presented, and workable legislation is not synthesized from them. there's no way forward, so long as the duopoly persists.
to state an obvious truth that does not need to be stated, but perhaps does need to be stated, ms. ocasio-cortez is an autonomous individual, and she's under no obligation to provide a medium for anybody to live vicariously through. if she's concerned about her career, that's her prerogative. but, the lesson here needs to be how impossible it is to get anywhere in a two-party system, and the absolute need to build a third party if there's any hope to get anything at all done.