Hunter, Texas courts deciding under Sharia instead of our Constitutions is not the problem, at the moment, although we certainly don't want that.
The current push by Sharia advocates is to have enclaves that can discriminate to exclude those who do not abide by Sharia, then to implement Sharia in ways that violate our laws and the rights of those living there, within that community. This sets up Constitution-free zones within our constitutional republic. This allows "marriage" to girls (i.e. pedophilia), female genital mutilation, and domestic beatings within these zones. As we are seeing in Europe, once those "no go zones" are set up, they serve as bases by which criminals can go out and rape women and kill non-Muslims.
As we know from 1400 years of history and the discovery of the Muslim Brotherhood plan for conquering America, the next phase is to completely conquer our governments and to replace our Constitutions with Sharia and the global caliphate. That's when even Muslim-convert women become second-class citizens, when non-believer women can be enslaved and raped, apostates and critics of Islam can be put to death, non-believers taxed when believers are not, etc.
I am in this to stop my grand daughter and her generation from that fate. As Barney Fife said, we've got to "Nip it! Nip it in the bud!"