It’s easy to support non-enforcement of immigration law if the bulk of the problem isn’t right in your backyard.
If you’re Texas, and the federal government announces it won’t do anything about a significant chunk of illegal immigration, you’ve got yourself a pretty big problem. The lawsuit is against the Trump Administration only because that’s the executive branch of the moment. It’s really against Barack Obama’s decision not to enforce the law, which is unconstitutional on its face would be an easy case to make in court if you were before judges who care about the law: