How do the American and Canadian populations overlap in their political spectrum?

[The Right Honourable Martin Brian Mulroney PC CC GOQ]

Liberal voters are Democrat voters, period. A lazy Democratic candidate could just take the LPC platform, make a couple edits, and run on that. Most Liberal voters have the same priorities as Democratic voters (again, except for a few things like universal healthcare which is just the status quo in Canada). AOC types or blue dog/right-leaning democrats' Canadian equivalents don't vote Liberal, but the Warren-Biden spectrum of the Democratic Party are hardly distinct from Liberal supporters.

The Conservative Party of Canada occupies a space that is hard to categorize in US terms. Most GOP voters would be well to the right of the CPC, that said, there are a lot of Trumpish/GOP-like Canadians who mostly vote CPC. A lot of people say things like "Biden/Obama/Bloomberg would be CPC if they were Canadian" which I think is completely wrong. I don't think the median Conservative voter in Canada would fit clearly into either the Democrats or the GOP, and Conservative voters would probably split halfway on balance. Canadian conservatism is a weird frankenstein coalition that often lacks consensus, and that makes it a hard thing to categorize. Using UK terms, the CPC coalition is a less classist, more pro-immigration, and less environmentalist version of the Tory coalition. (edited: even this is a very rough analogy though. Really, the Conservative Party coalition couldn't exist without Canada's unique characteristics. The GOP and the Dems are about equally powerful, while the CPC usually plays second fiddle to the LPC, so the people who vote CPC tend to just be people who don't like the Liberals and are right of the Liberals to some extent. Make of that what you will)

The NDP is basically the left wing of the Democratic Party if they split off. NDP voters are very similar to Sanders supporters in that a lot of their grievances come from a Liberal Party/Democratic establishment that is ostensibly progressive but governs in a more centrist way than they would like. There's also a third party element to the NDP that doesn't exist in the US, but by my understanding, it's comparable to some Lib Dem voters in the UK whose main thing is "the two parties suck, I'm voting for this weird third option". The Greens are a mix of this "third party/Lib Dem" element and the "Sanders/AOC" element, increasingly the latter (and hardcore environmentalists of course).

One interesting area of difference is age - polling suggests that the Liberals are pretty even in support across age groups, which is most definitely not the case for Democrats. Conservatives gain support with age, while the NDP/Greens lose support, but the Liberals stay fairly consistent.

Canada also has a more significant "rural left" because a lot of rural areas in Canada are quite remote and rely heavily on government services. Atlantic Canada, the far north, northern Ontario, and much of BC's pacific coast falls into this category.

Quebec has almost no political overlap.

[The Right Honourable Martin Brian Mulroney PC CC GOQ]

Canadian Conservatives have a very strong regional base in the Prairies (Great Plains), hence the heavy focus on support for the oil and gas sector and grievances against Liberals who they associate with the "eastern establishment."

Outside the Prairies (which has less than 20% of the population), Canada is super-liberal by US standards.   
 

Would you say that ultra-liberalness extends to daily life outside of politics (What foods Canadians eat, what media Canadians consume, what Canadians buy or do as hobbies, how they portray themselves, where Canadians desire to live, etc)?

Yes but in very few ways. One of the clearest examples of Canadian everyday liberalism is that religion is much, much less a part of daily life. One thing that always sticks out to me when I go down stateside is how often people will say "god bless you" or something like that in ordinary conversation, or how often I'll see random signs on billboards or bumper stickers that are very overtly Christian. This isn't necessarily taboo in Canada (except Quebec, public expression of religion is infamously taboo there), but it's just not a thing we do. Religiosity isn't that much lower in Canada, but people prefer to keep it to themselves, and it shows in our politics.

Canadians are also more politically correct, and you can imagine how this relates to our voting behaviour. Gun culture is also much less a thing here. Rural Canadians do often own guns, and there are definitely NRA types here, but it's far from mainstream. For the most part, gun owners treat it like a tool and not a cultural symbol or a god given right.

But for the most part, Canadians don't have more "ultra-liberal" lives than Americans. You'll see F-150s on the road even in big cities, you'll get invited to barbecues where you eat steak, drink Budweiser, and watch some pigskin, Canada's rural population as a % is almost identical to the US, and so on.

The reason Canadians are so much more liberal politically, while only a little more stereotypically liberal culturally, is that culture is less of a factor in Canadian politics. Regional identity and economic play a much bigger role. Hence why Calgary, a cosmopolitan, diverse city of 1M+ is overwhelmingly conservative, and the very white, rural, and elderly province of Newfoundland is overwhelmingly liberal. I general the normal American liberal/conservative stereotypes do hold true in Canada, but there are many exceptions and it doesn't matter nearly as much up here.

[The Right Honourable Martin Brian Mulroney PC CC GOQ]

I assumed Canadians are way more technologically progressive than Americans (less likely to use flip phones, more likely to own electric cars, less likely to listen to the radio and more likely to listen to Spotify, less likely to subscribe to cable and more likely to subscribe to Netflix, more likely to know what a "meme" is or what a "twitch streamer" is, etc).

I also assumed there's less of a sense of familial duty in Canada. Many American parents won't let their children cut them off. Many American parents are incredibly nosy about their children and demand full access to everything about them even in adulthood.

Am I wrong about these?
 

Those things are hard to say, I've always assumed Canadians and Americans are fairly similar those things (as with most aspects of daily life) but someone who's lived in both might have more of an insight.

On internet usage for example, Canadians seem a little behind actually. Just based on this I would assume Canada ranks a little lower than the US on the proliferation of technology.

Keep in mind that while Canada and the US have a similar urbanization rate, rural Canada can get reeeeally remote in some parts. Big chunks of Canada aren't even accessible by road, you'll have to get on a boat or snowmobile to reach some of these tiny northern settlements. The territory of Nunavut is bigger than Mexico, yet so inaccessible that not a single road travels into it, your options are plane, boat, or snowmobile.

Interestingly though Americans seem to be a fair bit behind on banking-related technology. Contactless/tap payments have been the norm in Canada for years, I really only have to use chip/swipe when I'm withdrawing money from an ATM. Sending/receiving money is also much easier because you can just e-transfer directly from your bank account instead of Venmo/Paypal. I don't think this has much to do with political preferences though, it's more that Canada's banking industry is basically a cartel of five big banks and one of the benefits is they collaborate on these things.

As for family commitments, I got nothing. I did a brief search for polling on the topic but I got nothing. It sounds like your point is true, but a lot of Canada/US perceptions are based on Canadians assuming all of the US is a Mississippi backwater trailer park and American liberals idolizing Canada as some utopia where gold falls out of the sky. If someone can find polling on this question or just some anecdotal evidence, it would be really interesting.

[The Right Honourable Martin Brian Mulroney PC CC GOQ]

Also there is image too, Americans like to think of themselves as the best in everything so naturally right with its emphasis on patriotism has advantage here.  Canadians tend to like to think of themselves as compassionate, polite, and for the little guy thus advantage left there. 

I think this is one of the best analyses of Canada's liberal tendency. Canadian patriotism is pretty left wing and somewhat anti-American. If you ask a random Canadian why they love Canada so much, the answer will probably consist of universal healthcare, multiculturalism, and peacekeeping.

I mean, universal healthcare and multiculturalism are hardly unique to Canada, and we haven't been a peacekeeper country in decades. But this is how Canadians see themselves. The stereotype of the polite do-gooder Canadian isn't just how Americans see us, it's how we see ourselves. I think this alone makes left-wing politics more appealing to Canadians.

The lazy analysis that I see from people on both sides of the 49th parallel is "Canadians are just more left wing than Americans". I think the median Canadian is to the left of the median American, but full-on leftists are as rare in Canada as they are in the US. There are elements of the American left that are pretty far to the left by Canadian standards, if Canada was just uniformly to the left of the US, you'd see Canadian politicians calling for the abolition of capitalism. I mean, Warren and Sanders were campaigning on workers' representation on corporate boards, something that not even the NDP runs on. Democratic socialism, as in achieving socialism through democratic means, seems much more mainstream in the US than it is up here.

Broadly speaking, I think Canada's political culture isn't shifted to the left compared to American politics, but rather "zoomed in" to the centre-left of American politics

[The Right Honourable Martin Brian Mulroney PC CC GOQ]

Also there is image too, Americans like to think of themselves as the best in everything so naturally right with its emphasis on patriotism has advantage here.  Canadians tend to like to think of themselves as compassionate, polite, and for the little guy thus advantage left there.  

I think this is one of the best analyses of Canada's liberal tendency. Canadian patriotism is pretty left wing and somewhat anti-American. If you ask a random Canadian why they love Canada so much, the answer will probably consist of universal healthcare, multiculturalism, and peacekeeping.

I mean, universal healthcare and multiculturalism are hardly unique to Canada, and we haven't been a peacekeeper country in decades. But this is how Canadians see themselves. The stereotype of the polite do-gooder Canadian isn't just how Americans see us, it's how we see ourselves. I think this alone makes left-wing politics more appealing to Canadians.

The lazy analysis that I see from people on both sides of the 49th parallel is "Canadians are just more left wing than Americans". I think the median Canadian is to the left of the median American, but full-on leftists are as rare in Canada as they are in the US. There are elements of the American left that are pretty far to the left by Canadian standards, if Canada was just uniformly to the left of the US, you'd see Canadian politicians calling for the abolition of capitalism. I mean, Warren and Sanders were campaigning on workers' representation on corporate boards, something that not even the NDP runs on. Democratic socialism, as in achieving socialism through democratic means, seems much more mainstream in the US than it is up here.

Broadly speaking, I think Canada's political culture isn't shifted to the left compared to American politics, but rather "zoomed in" to the centre-left of American politics

How do you think Canada would react if the United States adopted Universal Healthcare, made Puerto Rico a state (a smaller Quebec), and heavily downsized its military and made them into a peacekeeping force, All in the same year?

On universal health care, reaction would its about time.  Still even if US does go to universal health care, they are still likely to tolerate a lot more private involvement than Canadians tolerate.  It would likely be a mixed system not a government monopoly.  Now if they cover things like prescription drugs and dental care, which we don't, that would only increase pressure to follow.  One barrier is due to living next to US, both our corporate and top marginal tax rates can be a bit higher, but not so high it leads to companies and people with money leaving for US so that somewhat limits what we can do.  If US raises one or other, that gives us more room to raise them too.

As for downsized military, I think its more people don't like US starting foreign wars like Iraq, size of military most could care less about.  On Puerto Rico joining, doesn't make much difference as only 1% of population so much smaller impact.  

Do you think Canada legalized marijuana when it did because it was afraid of being "outliberaled" by the United States?

I wonder what Miles thinks, but I don't think this was the main reason. Trudeau tried heavily to appeal to young people. As a young Canadian whose first federal election was 2015, this was a big deal because even before legalization smoking weed was more common than cigarettes, so it just seemed like an outdated "THINK OF DUH CHILDREN" relic. Harper was also seen as a big "tough on crime/war on drugs" kinda guy (he literally said that marijuana was infinitely worse than tobacco...what a load of bovine manure), and by promising to legalize it, Trudeau reasserted his position as the more obvious anti-Harper option as opposed to Mulcair's deeply uninspiring and gun shy NDP.

I do think Colorado and Washington sparked the cause for legalization a bit, because it forced it into the public consciousness in North America. But I don't remember any overt or even implicit sense of "look how we're falling behind those redneck Americans"