Part of the reason the old SWC fell apart was because the Texas legislature was able to exert pressure on the whole conference. If we're already in a position where that is the case, we might as well get the band fired up because this ship is sinking.
I honestly think the fact that Houston is in Texas hurts their chances of getting in the Big 12. The more Texas schools in the conference the more real the possibility that all of the other conference schools could be beholden to an out of legislature. The fact that a Texas school is already jockeying the state legislature just to get in the conference should be a bold warning sign to anyone considering adding more Texas schools. The state of Texas has shown no qualms against using force to push an agenda on their own state universities and I think we're actually doing them a favor by keeping the Texas schools from holding a majority of the membership.
In short, adding more Texas schools would be a terrible idea.