I know about Oregon :
In 2000: It was because of Ralph Nader
In 2004: while Bush only lost Oregon by 4 he won nationally by 3 so Oregon was still +7 D in 2004.
So, although Old School Republican does a relatively decent job of pulling out the top-line numbers, there is massive lack of granularity or detail in his analysis.
Sure, it is absolutely clear that the Nader effect in 2000 was much more pronounced in the PacNW (Oregon in particular) than almost anywhere else in the US.
What is neglected in this analysis were the electoral shifts starting to kick in hardcore, where many parts of rural and small town Oregon were starting to abandon the Democratic Party in droves, while meanwhile the rapidly growing, Middle Class and increasingly Multi-Ethnic suburbs of Portland (Washington County) were starting to swing hard against the 'Pubs at the Presidential level.
Gore was able to retain a rump base of ancestral Democratic support in rural areas and Mill Towns, despite the Nader effect hurting him hard in the margins in the Progressive Democratic stronghold neighborhoods within Portland, Eugene, Corvallis, and Ashland (Not to even go into Coastal Oregon, Mid-Valley Cities, and various rural parts of Southern Oregon).
In 2004, there was a major pro-incumbent swing in many parts of rural and small town Oregon essentially rallying behind the flag, before we started to see the body bags and military funerals in our small town communities....
Meanwhile, in the larger cities and suburbs, Anti-War sentiment was already starting to hit critical mass, because Oregon National Guard units faced a disproportionate share of military casualties because of Donald Rumsfeld "Stop Loss" program, lack of support for Up-Armored Humvees, and as one of the Top Five National Guard Units in the Country we filled the gap in the early days of the Occupation of Iraq....
It wasn't until '05 and '06 in the small mill towns and rural parts of Oregon where sentiment started to shift heavily against the Iraq War....
I am firmly of the opinion that this explains some of the dramatic swings towards Obama in '08 in various rural communities and Mill Towns throughout Oregon, were more a belated reaction to the War, than a response to the Great Recession of '08.