Before people get all up in arms about the veracity of threats to close the US/MX border, TX comprises the vast majority of the border economy. CA, on the other hand, has basically two industrial border zones - Calexico/Mexicali & San Diego/TJ.
I'm not sure San Diego could handle that many shipments. It's a very small port for containerized shipping. Los Angeles/LB are way overcapacity...Houston might be all right though.