Honestly I’m not sure it’s possible to make DRM illegal. On what grounds with that be constitutional? Artists have had rights to control how their work is performed in the US forever. How is this any different? Why would one form get protection and not the other?

I mean legally I don’t know if this counts as a free speech argument or not I just don’t see how such a long would end up passing muster.

This the only possible way to win on the long run.

Would an anti-DRM law actually be constitutional?

What part of the US Constitution would make it illegal? Companies should not have this kind of power. Internet is a basic need now, it's where we (as a race) create and share knowledge. If it is immoral to put restrictions on book consumptions, why should be moral to put restrictions on media consumption? And I'm not referring to access. You can buy a book on a store, and after that that book is yours you can lend to anyone else, and everyone can read the same pages on this same physical book. It the right to use the information after that you paid for it.

Yes, why not? Believe it or not it's not an issue Madison ever weighed in on.