I honestly have no idea what you’re talking about, left leaning Americans seem to talk about Canada positively all of the time, in reference to its health care system and generally aboit how they want their country to be more like Canada. The only thing negative they say is in reference how native people have been treated and still continue to be treated there which I think is right.
I am not from either country and this is just based on what I see Americans online say about Canada/Canadians.