[AmericanExceptionalist]

In the late 1930s and early 1940s, northern California and southern Oregon almost seceded from the rest of their respective states, in order to form the new state of Jefferson. Only the sudden intervention of WWII broke the secessionist momentum.

Going back a bit further, in 1861, east Tennessee almost seceded from the rest of the state when Tennessee joined the Confederacy. (Most east Tennesseans were pro-Union, whereas most west Tennesseans were pro-Confederacy, and a slight majority of middle Tennesseans were pro-Confederacy also.) In fact, the western portion of Virginia did secede from the rest of the state, thereby forming the new state of West Virginia. So this hardly seems like a jaw-dropping idea...

[katana]

Most East Tennesseans were pro-Union, whereas most West Tennesseans were pro-Confederacy

Same situation in Kentucky. Scots Irish Appalachian Mountain people vs. the wealthy plantation and river folk to the west. Kentucky (barely) stayed in the Union. The major reason why the Emancipation Proclamation applied only to States in rebellion (the Confederacy). Otherwise it was feared that all the border slave States would swing.