Yeah no California would not be widely welcomed as part of Cascadia, not even NorCal alone I don't think (where NorCal = San Francisco's general region and all points north.)

This is the most expansive realistic proposal for Cascadia:

(larger version linked)
Being fairly strictly geographically and bioregion-based, it's overly-broad. I don't think the Snake River Plain in particular would fit in well with Cascadia at all, myself, and parts of eastern Oregon and Washington might not be too enamored of it either (the Spokane region and North Idaho in particular are closely-knit, and historically haven't been too fond of the western and southern parts of their respective states either; I could easily see them joining up together in the turmoil of Cascadia's creation.) I can't speak at all for the BC side of things (and up to Southeastern Alaska? Um, maybe?), Kereb I'd love you long time if you could opinionate on that a little bit

But that tiny little blip into California on this map, based on what I know of the area, they'd probably fit in very well with Cascadia. (This image gives you a better idea of where that area and others are in relation to the current borders; do take note however that it was drawn based on watersheds, and thus the boundaries go too far north south and east.)

edit: just noticed this:

quoting kodé:

I doubt any actors would get elected to office in Cascadia.

For the most part that's true, but I could easily see some of the more hardcore former-actor-now-green-activists getting elected, tho maybe not to executive offices.