If it were'nt for Portland Gore would have lost Oregon to Bush.
This is generally true of most states Gore won if you remove their largest city. (Depends a bit on what city lines look like, of course.)
I will also posit that 2000's focus on gun control as an issue made interior Oregon (and Washington) more hostile than usual to Democrats. But of course Nader was the major factor.
2008 was an anomaly compared to the most recent Presidential elections. It may be becoming the norm in Oregon, however; the most conservative factions are ascendant in the state Republican Party.