OK, how would the secessionist you mention handle this situation :
a person getting social security was born in Texas to Texas born parents.
To where would that person be deported?
LOL you’ll have to ask them.
And until there are some elected officials in the state actually advocating the process, I don’t see any way it can happen.
So far there are ZERO, NO, NADA, NONE officials elected to a Texas state office that advocate secession that I’ve been informed of.