On the last point, it seems to descriptively still be true, based on the outcomes of recent elections? SF itself is obviously quite to the left, but even within SV, Democrats almost always win, and pro-spending ballot initiatives usually pass with healthy margins, even when they involve tax hikes-- e.g. the 1% surcharge on >$1m incomes from 2004, or the recent high-speed rail bonds. HSR in particular strikes me as in line with a Bay-Area techie/leftish/optimist spirit, in favor of large, tech-flavored public works projects.

There are some "business conservatives" in the region, but somehow I don't associate them with tech or SV, Meg Whitman notwithstanding. When I think Bay-Area conservatives, I think east-bay hills and suburbs, or north bay, commuting in to the financial district, not Mountain View. But maybe that's not accurate?