It’s almost certainly unconstitutional, but there’s not specific case law so it has to be litigated to know for sure. So there needs to be people charged who have the means and willingness to go through several years of trials and appeals. And they have to maintain that motivation for a long time - some cases drag on for a decade or longer.
The point isn’t to make it illegal forever, it’s to scare people and organizations without the resources to engage in a legal fight to stop supporting interstate care for the next three or five or ten years.