Results by Metropolitan Statistical area starting with the most populated:
Dallas/Fort Worth: McCain 55%-45%
Greater Houston: McCain 54%-46%
I am aware that Travis County went heavily Democratic, but is it large enough to offset much of Rural Texas, especially when you consider McCain got over 70% in pretty much every country in West Central Texas and Texas Panhandle and over 70% in most East Texas save a few with large African-American populations.
Although the numbers seems reasonable, how the heck did the statewide results come out to 55% McCain and 44% Obama when aside from the Hispanic South, McCain won most of rural Texas by a landslide, in most cases over 70% and in many cases over 80%.
Travis County (Austin makes up about 3/4 of the population) was won by Obama 63.52-34.25
As was stated much of rural Texas is sparsely populated. Obama won Travis County by a little over 117,000 votes, the largest vote advantage either candidate had in any county in the state.