Of course, but nothing to the tune of 90% outside of the Castro or Haight. This area is full of granola eaters and latte drinkers- that embraced the counterculturist lifestyle and were unable to reside in a traditional American community.
The 20th most Democratic city in California is hardly unique for having heavily Democratic areas.
https://uselectionatlas.org/FORUM/index.php?topic=94829
Of course not, but Mill Valley does not vote 90% Democrat. Us White Californians voted for Romney.
Mill Valley 2012 Presidential Election
Barack Obama 81.5%
Mitt Romney 16.2%
Mill Valley 2010 Gubernatorial Election
Jerry Brown 78.6%
Meg Whitman 19.9%
I could point to a litany list of very affluent white Californian suburbs, small towns and urban neighborhoods where Barack Obama received between 80% and 95% of the vote in 2012. Cities like Rancho Cucomonda or Bakersfield or Yorba Linda are outliers: white Californians are not conservative. I'd estimate that white Californians gave Barack Obama around 48 - 50% of the vote in 2012. The preponderance of evidence does not suggest that white Californians are "conservative" or that they supported Mitt Romney.
Atherton (Median Household Income: $250,000, 80% White )
2012 Presidential Election
Mitt Romney 51.5%
Barack Obama 46.6%
Piedmont (Median Household Income: $149,000, 74% White)
2012 Presidential Election
Barack Obama 74.8%
Mitt Romney 23.4%
Orinda (Median Household Income: $187,000, 82% White)
2012 Presidential Election
Barack Obama 62.7%
Mitt Romney 34.7%
Danville (Median Household Income: $129,000, 83% White)
2012 Presidential Election
Barack Obama 49.8%
Mitt Romney 48.3%
These data points hardly support your notion that whites are aggressively trending towards Republicans due to the supposed race war initiated by Barack Hussein Obola. Outside of the old Confederacy, whites are pretty split between the GOP and the Democratic Party. That's not to say that they didn't support Romney in 2012 but they're a core constituency of the Democratic Party in Washington, Oregon, California, Minnesota and New England.
Only ignorant fools believe the narrative that white "makers" vote for Republicans and that brown "takers" vote for the Democrats. Wealthy white urban neighborhoods have consistently voted for Democrats at rates that are nearly comparable with working class African-American neighborhoods or working class Latino neighborhoods.