Just out of curiosity, but from what I read really quickly (don't know much on the topic) but were Papinau's problems stemming from his hardline approach which alienated many potential supporters? Considering the sheer scale of support that his party held in parliament, it definitely seems like he had the level of support necessary.
What would happen if Louis-Joseph Papineau and William Lyon Mackenzie
Had succeeded in their respective rebellions?
Could we have a republic of Canada today if they had won? And what would
The consequences be for Britain?
If the US openly aids Canadian rebellions, and their success does not stop or butterfly away the South seceding in the US then might not Britain think its their turn to do the kicking?
The South may secede sooner seeing that more Northern territories means more "Free" not "Slave" States.
Papineau wasn't really the problem and was if any thing a moderate. It's mostly other Patriote leaders such as Nelson who really made it difficult to get wider support. He could be said to be a proto-communist whose ideas about equality freaked out the middle class, seignorial class and the clergy the last meant in turn that you had priest directly preaching against the uprising which, considering how catholic people were at the time, was a big deal.
The last point that a large part of the population had only a vague idea of the issues. They had lived under british rules for 70 years without too much problem on a personnal level and the lack of powers of the Assembly probably didn't seem like something that would impact them in any real fashion.
So what this mean is that you would need, in both canadas, a casus beli that is easier to understand for the common inhabitant as well as a manifesto that would manage not to alienate potential supporters.
At best, you might get "benevolent neutrality" where the US claims official neutrality but lets the rebels use its territory for recruitment and training as long as they are not too obvious about it.
Was there really an issue that reached across the linguistic and religious lines which could unite the lower classes in each province though? I admit I struggle to think of one which would be capable of overcoming that divide, as the revolts in Canada East and Canada West were practically separate events for all intents and purposes.
To be fair, that was basically what the Patriotes and Hunters Lodges got historically. The US only cracked down on them after the attacks in 1838 had largely been carried out.
So you think that America could've help the rebels if they kept it a secret. So if that works what do think is more likely a new independent republic or those territories joining America?
Assuming that the previous occurs, and Upper and Lower Canada manage to establish their own republics, wouldn't it be more complicated than just saying that one would eventually go to the US like Texas? If I recall correct, the majority of BNA at the time was Canadien; excluding the Maritimes, it was most definitely Canadien majority. It seems unlikely for an Ontario approaching OTL boundaries to be established considering population discrepancies.
Would it be more likely that there would be a single French-majority Canada, which then might try to sign an alternate version of the Webster-Ashburton treaty to hep delineate the border? I just don't see the two Canada being successful as one that is united, even fi the united one loses a few border areas that are heavily english speaking (Southern Ontario, perhaps?)
Both Upper and Lower Canada (east/west came after 1841)
The assembly being powerless to prevent the Governor from doing whatever it wanted. If you get him to increase taxes to cover some personal spending or to reimburse government money to make loans to friends (something), the lower classes would start to feel involved especially if their elected representatives are clearly powerless to do anything.
Another possibility along the same line is that the Russell Resolutions, instead of relieving the assembly of its power to vote the civil list to give it to the Governor propose instead to defer further the matter for consideration and instead authorize the governor to raise a special levy to cover the arrears of the provincial government. By putting things in limbo you give Patriotes & Reformists leaders more time to stew in their indignation and the population end up being charged twice for the same amount of services.
Lastly, an unwise but plausible move from the british could be simply to ban political parties from the assembly based on a strict interpretation that people represent ridding, not parties. Using that excuse, some politician could be barred from running by charging them with violation of electoral laws. While the real amount of power held by the assembly was small to begin with and their actual impact on society would see little change, it would be easy to make the politicians into martyrs and present the government as taking away the franchise altogether.
Something else that might inflame people would be things heating up in madawaska unlike the anti climax OTL. Militia have been used in the past during conflict but not usualy outside their own provinces, if you force people to go and fight at a distance meaning that their crops might go to waste, you've just pissed off a lot of people.
They actually stopped some attempted incursions when they were aware of them. Not strict neutrality but the US government was still fairly serious about not getting dragged in. Imagine if on the other hand they chose to recognize the status of belligerent to the patriotes with weapon being sold openly to them as long as invasions weren't mounted openly from US territory.