We already know from FoIA emails that in the last round of expansion the Big Ten very nearly added a squad of B12 teams including Texas, and that the deal was largely sunk by Texas politicians demanding the Texas universities went as a package deal (Big Ten wouldn't, and won't, take Tech).
Why doesn't the Big Ten call Texas today and offer a better deal? They have more money than the SEC, an easier schedule that doesn't include a likely annual beat down from Bama, membership in the research group worth all the money everyone wants into.. it's obvious the Tech thing isn't an issue anymore.
The only thing the SEC can guarantee Texas is shorter drives and a tough time winning.
And if we landed Texas that could make a 16th spot all the more enticing for a Notre Dame... Or at least soften the blow of adding Kansas/Mizzou/etc.