I’ve been to Oregon 5 times.
I’ve been to Eugene, Salem, and Bend. And sure, they’re not nonexistent, but they’re nothing in comparison to Portland. But Eugene and Salem lean Democrat anyways.
In a number of elections, majorities in the three Portland counties (Multnomah, Washington, and Clackamas), Marion (Salem) and Lane (Eugene) have carried the day against majorities in the other 31 counties, so your analysis, in general, is spot on. At the same time, there is a decent demographic of the state (or at least was when I was growing up in the ‘80’s), particularly in the southwest, that is democratic in the West Virginia/Arkansas tradition. People who voted for Carter in ‘80 because Lincoln was on the wrong side of the civil war//no one in their family had ever voted democrat. These folks will think twice before voting for a black man from Chicago—and in thinking twice may discover some reason beside race to stray from the D column. This might push the R majority up even larger in the SW, and cause Lane County to be a draw. If that happens, Portalnd and Marion may not be sufficient to carry the day for the Democrats.