2008 Trend Map
What's the deal with the counties around Lubbock (the pink splotch in the panhandle)? Is it just random? Because it sticks out against all the rural counties nearby. No Germans up there, and as far as I know, not a significant black population. There are some Hispanics, but no more than in the surrounding areas that trended McCain.
South Plains. The Panhandle is the part that sticks out between OK and NM.
Looking at the results it appears mainly to be a bounce-back from anomalously high Republican percentages in 2004. The particular area has much more of a farming base than the the surrounding areas. It is the heart of the Ogallala Aquifer. To the east you are below the Caprock and into more of a ranching area. To the south, you are also below the Caprock and into the Permian Basin, where oil is dominant. To the north (in the Panhandle) your are more into wheat, ranching, feedlots, and oil. If you look at the population map, you will see the rural counties around Lubbock are actually a bit more populated than the other rural areas in West Texas.
This is an area of fairly recent (post-WWII) development, with many of the counties hitting their peak population in 1960 - quite late for an agricultural area. This is because the technology to effectively irrigate did not exist in earlier times. I think you are going to see a bit more populist voting pattern than in areas that are based on oil, cattle, or wheat. On a populist scale, Bush is more populist than Kerry; but Obama is more populist than McCain. Running against Texas works in New York or California or Massachusetts. It doesn't work in Texas.
The reddest-trending county is Terry County to the SW of Lubbock. In 2004 it was 80-20 for Bush, in 2008, it was 67-32 for McCain. The bottom fell out of the Democratic vote in 2004 (dropping 29% from 2000), but there wasn't that much of a shift to the Republican side, which suggests that many Democrats didn't vote. In addition 2004 had a much stronger Republican GOTV effort, as Bush wanted to make sure he won the popular vote. In 2008, McCain was more concerned with holding on to OH, VA, NC, and FL.
In 2008, some of the Democrats voted. Some of the Republicans stayed home. And some of the Bush-voters switched to Obama. Turnout was higher (as high as 1992). But, the 2008 Democrat percentage is about the same as the 1984 Democrat percentage (Obama did as well as Mondale).
If you look further east, you will find areas that voted Democratic in 1996, but were some of the strongest Blue-trending areas. These areas are losing lots of population, and the Democrats are literally dieing off. You will see a similar pattern in the rural counties in east Texas. These areas are still trending to the GOP, and there hasn't been a correction.