I’m not sure how strong it is at the moment, but years ago that was the idea for eastern Oregon and Washington to join with Idaho. I have no idea how feasible that would be.
I would imagine that even though the liberals in Olympia and Salem hate those people, they will never let them go even with plebescites favoring secession to Idaho. You have the same trend, not as developed, in downstate Illinois and southern New Jersey.
I think that idea is picking up steam, especially with Oregon. Have been hearing it often recently.