California to the left of the line from the Baja cut to San Francisco Bay is not part of the continent at all. It broke off and it's firmly planted on the Pacific Ocean floor. The only way it's going to slip is north because that's the direction the ocean floor is moving.
So when people say California is "different", that's just natural since we're not even part of the continent. Note that Californians to the right of the falt voted with the Red States (but there aren't a whole lot of them).