Here's a way I look at it. Seattle/Puget Sound is basically the Bay Area, except maybe 10-12 years behind it's Democratic trend.
However, despite being large, the Bay Area is still only about one-fifth of California. Even with Los Angeles thrown in, the Democratic core can still be overpowered by suburban Los Angeles (within the county as well as others like Orange etc), San Diego, and the rest of the state.
What does Washington have that can overpower Seattle? The eastern part of the state is already just about as Republican as it can get. Metro Seattle makes up almost two-thirds of Washington.
The Governator's performance in 2006 should be considered by the people saying California.
According to population estimates, the only other areas of the state that seem to be growing enough to even partially offset King/Pierce/Snohomish counties are Clark County (Suburban/Exurban Portland) and Spokane County. Franklin County (Pasco) appears to be the fastest-growing in the state, but it's still fairly small, with a population just over 70,000.
I wouldn't place my electoral hopes on families priced out of Portland or newcomers to a reliably Republican county. And while I don't know exactly what's driving Pasco's growth, from what I understand, the city is becoming more and more Hispanic.
That being said, I give a slight advantage to California over Washington as the state least likely to vote Republican because a higher percentage of Californians would have to switch their votes to change the result there.
Your comparison to the Governator is inapt. New York City has elected a Republican mayor for the past 16 years. Yet the chances of NYC voting for a Republican president, Senator or House members (outside of Staten Island) are close to zero. State and local politics don't necessarily translate into national politics.
Is it? Modern Seattle would
never elect a Republican mayor. And Angelides only got like 38% for Governor. Stuff like that doesn't happen in Washington.
Yeah, there is Spokane/Vancouver/Tri-Cities. But they're still small compared to Metro Seattle. There's also other liberal areas in Washington like Bellingham that counter these areas to some degree. And the coast is reliably Democratic (though a more working class kind).
Franklin County is about 60% Hispanic as of 2008. They're newcomers and they don't vote yet (immigrants and under 18). While I'm not willing to say Hispanics will remain as Democratic as they are right now, they will most definitely not be voting 65-70% Republican anytime soon IMO. If you look at older established Hispanic communities in Washington (with people who can vote), they're some of the most Democratic cities in the state. My point with Franklin County is--it's not going to stay so Republican for too much longer. I suspect it will turn into a swing county once the Hispanics start voting.
Spokane and Vancouver/Clark can (and often do) vote Republican--Spokane County usually does (the city itself is lean Democrat). Vancouver/Clark however was traditionally a working class Democratic county like those on the coast, and I think there are still some remnants of it. Portland's suburbanization has made it more conservative, but I suspect that will wane in time. But either way, while these two counties might go up to 55% Republican or so, they will never ever be as lopsided as Seattle is with Democrats--not to mention nearly as populated.