Why are the Berkshires in Mass so liberal?

[Benj]

Like most liberal/Dem leaning areas, much of the answer can be summarized in two words: social issues.  

Plus, it's in Massachsuetts, one of the most (if not the most) liberal state in America.

No, but the Berkshires are a special kind of liberal; they voted for Coakley, when equally liberal areas voted for Brown.

I'd say that other posters are right when they describe it as a southern Vermont appendage.

Hmmm? No equally liberal areas came close to voting for Brown. The areas that voted for Brown were less Democratic (and far less liberal) suburbs and exurbs of Boston and smaller cities (Worcester, Springfield, Lowell, etc.). The swing is not completely uniform; generally, the less Democratic an area is, the greater the difference between its 2012 Presidential and its 2010 Senate vote. But the super-liberal areas, whether in the Berkshires or in Cambridge, were all solidly for Coakley. As were the rich liberals on the Route 2 corridor; Belmont, Arlington, Lexington, Concord, Lincoln, Acton, etc. all voted for Coakley, as did the comparable Newton and Brookline.

Coakley was also from the Berkshires (North Adams), so even if her performance had been unusually strong there (it wasn't), that shouldn't be a surprise.

If you're having trouble remembering, here you go:

http://www.boston.com/news/special/politics/2010/senate/results.html

[Benj]

A cold climate does seem to have an liberalizing effect on white people

generally true but L.A. is pretty liberal.

Are there any non-Hispanic, non-gay, non-Jew, run of the mill white people there? A large enough population to make any sort of generalization anyway?

Most of West L.A./Santa Monica is fairly liberal and White, but this is more a factor of urban density than anything else.
It's true that small town/rural liberalism seems nonexistant in warmer areas, except maybe in parts of Hawaii, Asheville, and New Mexico. Am I missing anywhere else?

Nowhere that I can think of other than college towns, which shouldn't really count. Of course, that's misunderstanding cause and effect: The rural South is conservative because of its climate and thus its agricultural history, rather than the rural North being liberal because of its climate. (As the Plains and Mountain states show, being cold and inhospitable is hardly a guarantee of rural liberalism.)