Even though about half the threads in the South forum seem to be related to Texas, I don't see the critical mass for splitting it. The total post count just ain't there.

I suspect that pretty much all the Texans who'd answer questions about their state know where those posts are, so having them as part of the South (U.S.) forum isn't a problem.

(The New England forum is more active than the South forum, and about half its posts relate to Massachusetts, but I don't see any need for a separate Massachusetts forum either.)