Northern Idaho actually has quite a lot of left-leaning politics/culture. Southern idaho is where all the conservatives live (and the vast majority of people generally).
yes, northern idaho, I remember all the left leaning skin heads. . . /s
It has more leftists than southern Idaho, but still, it's not exactly a bastion of progressive thinking. In fact, the state legislator doesn't have a single dem elected north of the boise metro, so I'm not sure how you're quantifying it?
Ehhh... I'd say that the left leaning people are basically all in the Boise area (Ada county) Sort of west center of Idaho. Beyond that, it's trump town pretty much everywhere else. Especially the pan handle where all the neo-nazis live.
Really only Moscow where the university is, and maybe pockets of CDA. Where-as Boise, Meridian, Twin Falls, and Pocatello are all fairly centrist/left-leaning.
"Northern Idaho" used to be shorthand for "extreme right wing" due to it being the location of the headquarters of the Aryan Nations and location of the Ruby Ridge standoff. Those references are over twenty years old now, so no idea how much that ideology survives there.
Even NPR's Maria Hinojosa couldn't find any "Nazi Town" in Idaho, as she had expected to. See the "Our Private Idaho" episode of "America By The Numbers":
https://shop.pbs.org/WC6542.html