Overlooking the patronizing use of "y'all" in your reply, as a matter of fact, he wasn't correcting a mistake, he was running from a fight with the NAACP, which wanted to stereotype him as a string-tie, Colonel Sanders planter and/or pickup-truck-driving Negro-dragger.
Gary Bledsoe of the Texas NAACP tried to pick a fight with Bush in 2000 about a couple of bronze plaques on public buildings that had been erected (in one case at least) with funds left over from the Confederate veterans' relief funds (the ones usually appropriated for e.g. artificial limbs -- Mississippi was spending 20% of their budget in the 1870's that way). Bledsoe wanted to play bloody-shirt politics, and so Bush redefined himself as a "southwesterner" not a Southerner, n/w/s that Crawford is quite securely located in the part of the State that, fully settled and populated by then, seceded from the Union in 1860.
If he had wanted out from under the hostile and pejorative assignment of Southernness, he could have claimed that he was a Connecticut Yankee with roots in Kennebunkport, Maine, instead -- but he didn't. Instead, he threw over the millions of other Texans who are Southerners, and disowned them by trying to invent a new distinction without a difference, of a "southwestern" white Texan who somehow isn't "Southern". Nice work if you can get it.
In essence he said, "no, no -- of course, yes there are millions of other white Texans over there who are a bunch of racist, knuckledragging crackerheads -- but I'm not one of them; I'm southwestern, not a crackerhead like them!" Which is a nice way to stand up for your neighbors, something that people in the upper reaches of the Republican party seem particularly good at not doing whenever the 'Rats decide they want to play ugly.
Loyalty works both ways, Bob.
Yes. And it was still going on today, if you caught Fox's Beltway Boys. Mort and Fred were seething, fuming--almost as if they were angry men, or something--using the new "n" word (nativist) to characterize the CLASS (yep, CLASS) of folks they also described as "Right Wing Talk Radio Types."