If this fails it'll be because the tech industry expresses disapproval too loudly to ignore.
The legislators don't care about the underlying criticism. Almost no legislators have ever used a 3d printer or written any software, beyond maybe simple assigned programs if they had a required intro-to-programming course. Few are "tech" people. The rest don't understand this technology, or any technology really, beyond it being a black box for specific purposes. They see 3d printing and plastic guns and think something must be done, because the 3d printing black boxes are producing dangerous weapons.
Note that this isn't really limited to guns either. I foresee a similar moral panic wrt 3D printing "killer drones" (i.e. parts that allow one to attach explosive to a drone) and software that allows you to circumvent various restrictions on drone firmware. All it'll take is one high profile attack using a drone...
The only thing that's different about this one is that it mentions a technology geeks care about. But I doubt that's enough. As another commenter noted, you can no longer hide behind "we have no technology to distinguish between guns and non-guns". We have AI that's supposedly PhD-level and will soon automate all jobs. Looking at STL files sounds like a job.
That's actually one of my fears about LLMs: they make thought policing cheap. There are profound privacy and cost barriers to having a Facebook employee review all your private messages. There are no such barriers to having a robot watch all your IMs in real time.
Or your literal thoughts depending on how far we're able to push neuralink type technology.
USA has plenty of saner places. In fact, one could argue that CA is a local minimum for sanity in USA
There is a reason why California is leading the nation in migration out of the state.