How does a guy that would be someone that would find themselves arguing a case in front of the Supreme Court not have prepared to answer that? That seems basic.
I mean, it's basically a rhetorical question since everyone knows Texas cannot do anything about New Mexico's standards. In sure he would have liked to say "fair point."
Also, the article above is clearly one-sided, so his answer may have been adequate in the eyes of other non-pitchfork wielding reporters (haven't seen the transcript myself though).
I suppose he could have said something along the lines that Texas is trying to lead the way in improving clinics and the point is to encourage a higher standard, not to shut anything down. If there is a market for abortions in that area, someone will respond and set up a complying clinic in that space. In the meantime the residents in all reality will go to the cheaper nearby clinics in New Mexico. If and when New Mexico follows and implements similar standards then the market will definitely respond with complying clinics.