I can't help but think that this would be a vastly better deal for the US than Canada. Canada already enjoys much of the benefits touted for a merger (protection of its neighbour, Free trade access to a massive market) while the US has much to gain (massive resources, land, water, better healthcare).
Assuming there was as much in common politically and socially as suggested (there most certainly isn't) the US's stock is very much in decline while Canada's is very much in ascendancy.
The only way a merger could happen would be as a merger of equals necessitated by bigger global threats alongside dramatic social reform/normalisation in the US (I.e. The US starts to catch up with the rest of the Western world in terms of social maturity).
Assuming there was as much in common politically and socially as suggested (there most certainly isn't) the US's stock is very much in decline while Canada's is very much in ascendancy.
The only way a merger could happen would be as a merger of equals necessitated by bigger global threats alongside dramatic social reform/normalisation in the US (I.e. The US starts to catch up with the rest of the Western world in terms of social maturity).