Santa Cruz County, California must be up there. The opening of UC Santa Cruz in the mid 60s has transformed this traditionally Republican coastal county into one of the most hard-left areas in the country (Angela Davis is a professor at UC Santa Cruz, 'nuff said).
No, a lot of the shift happened because the Republican party went crazy hard right. The university played a role but the trend is seen all over the bay area, and really accelerated with that dumbass Bush. Acting like some sort of uneducated redneck is not going to play well in that part of the country.
Yes, Dubya was toxic for CA Pubs. Beyond Dubya being Dubya, Californians just don't think very highly of Texans in general, and loathe their accent and cultural style as a crude generalization. The accent thing matters. I think that is one reason why Carter did so poorly in CA, and Tunney with his Boston accent went down to Hiyakawa. You may think I'm nutter, but I really believe that.
Oh I absolutely believe you. Hey in seeing it in action now with the looks I get when I say I live in Tennessee. 
Santa Cruz did indeed trend heavily D after the university opened. Many of Santa Cruz's older established families are the core of the R vote in the area.
1960: 39.9%
--Skip 1964--
1965 - University founded
1968: 41.0%
1972: 46.4% (1968 => 1972 should be seen as unprecedented for a positive D trend, and it was probably due to UCSC's student body increasing)
It actually also rejected FDR in 1940 and 1944.
