Don't live in Austin. Austinites are pretty good at marketing themselves as progressives surrounded by the 'rest of Texas', but the reality is, as always, a bit more complicated.
I have never lived in any of the other major cities in Texas, so I certainly don't understand the full dynamics of their politics. I do understand that at the heart of the major cities they tend to be more liberal, which is expected of just about any major city. However, as an Austinite I can say it feels like the liberal bleeds more into the suburbs here than in the other major cities. This may be because of Austin's relatively small size or just bad anecdotal evidence. Take that as you will and I hope I didn't rustle too many jimmies.
I think that's mostly due to Austin's small size and exclusivity, but it's also a lot of 'image' that Austinites like to reinforce. I also find it entertaining that the self-described most 'progressive' city in Texas is actually the least diverse major city in Texas, with ~70% white population. Don't worry too much about the regional politics of Texas, especially if you don't live here - it's often quite maddening. :-D
I agree that central Texas also has its fair share of conservatives, but how does the Wikipedia article about Houston prove this? Houston is 2.5 hours from Austin.
So, I generally don't equate 'Democratic Party' with 'Progressive' anymore, but at the state level I'll admit that one is at least closer than the other.
Did you read the rest of that paragraph? The cities tend to vote Democratic in state elections whereas the rural areas overwhelmingly vote Republican, and Texas has a lot of rural space. I'll also point out that the largest city in the U.S. to elect an openly gay mayor (reelected twice) is Houston, which I found entertaining because of the two Democratic candidates, she was the more 'conservative'. Austin isn't as 'weird' as it thinks it is.
It's the Houston suburbs that are Republican, whereas the rest of our vast spread-out city) leans Democrat. Houston has one of the first openly gay mayors of a major U.S. city. From the Wikipedia article: "The cities of Houston, San Antonio, Dallas, Austin, and El Paso all presently have elected mayors with Democratic ties, and have voted Democratic in recent statewide and federal elections. However, the suburbs of these cities remain heavily Republican."
http://en.wikipedia.org/wiki/Houston