Will this happen?  Naw. As memory serves, breaking states apart requires as much support by Congress and the states as passing a new Amendment. Still, fun to think about. And… let’s say the counties vote to leave Oregon and join Idaho. Let’s say the vote isn’t even close; it’s a landslide. If the people and county government just simply start *acting* like they’re part of Idaho, refusing to listen to the Oregon state government, keeping their own tax dollars, etc., what can the state of Oregon actually do?

Five Oregon counties to vote on leaving state, escaping to ‘Greater Idaho’

Note that the map also shows parts of California as part of Greater Idaho. Personally, if this sort of thing was even vaguely possible I’d recommend the relevant Oregon/California counties break off and form their own *new* state, and score themselves two shiny new Senators in the process. Then eastern California can break off from the coast; Illinois could secede from Cook County; New York State could break away from New York City.

Being too lazy to look it up, I don’t know offhand if it would be Constitutionally easier for a chunk of one state to join up with another than it would be for a state to break up into several new ones. If it is, then, yes, joining with Idaho makes sense: who in their right mind would want to be run by the same government that runs Portland?