That's a very recent development -- starting around 2008. Even still -- beside Austin -- they are barely liberal. You do realize places like SF, Los Angeles, NYC, Philadelphia, Boston, Chicago, Seattle etc vote democratic at rates close to 75% for like 30 straight years.
Even most southern cities like Atlanta, Jacksonville, Tampa, Orlando, and Miami are well into the 60s.
Even if Dallas, Houston, and San Antonio are like ~52% for the last 8 years, they're a bit of an outlier as far as major cities go.
