@Azure @green @Elizafox I would argue that it's stronger than you give it credit for being, if not in the sense of a shared culture, then at least in a shared set of values that aren't shared by the dominant cultural rivals. It's not universal -- looking at Bellevue, here -- but I do think it exists. Not at the state level, but then, the whole state doesn't have to secede. It's not like if we're talking about breaking one political union, we can't break two or three.
@Azure @green @Elizafox I rather like the quote from Thomas Jefferson on that page: "I would rather the States should withdraw, which are for unlimited commerce and war, and confederate with those alone which are for peace and agriculture." (( https://en.wikipedia.org/wiki/Secession#Justifications_for_secession ))
@Elizafox @green @Azure Plus, Estonia's not the only example, merely the first one I grabbed. There's a fairly extensive like on the Wikipedia page on secession, as well as a list of identified causes of which I think a Cascadian secession movement would easily qualify: self-determination, preserving diversity, ending discriminatory redistribution, providence of superior constitutional systems.