Austin (and the Dallas/Ft. Worth area) is really different from the rest of Texas. Most of Texas is... well, it's pretty stereotypical, honestly. But Austin and DFW really only got a population boom in the past few decades, with a lot of people coming in from other states, especially the North and Midwest. As a result, most people in the cities don't have heavy Texan accents, everyone is either from somewhere else or their parents were, and I like to say that these areas are the least Texas parts of Texas. DFW even moreso than Austin.
Also, Austin is the one steadily Democrat city in the hugely Republican Texas.