Why does Trump want to pass the Save America Act so badly?

I know you have to show you live in the USA and a legal resident here. I know there is something with birth certificate and maybe social. Yeah that is a huge inconvenience, not all of us know where are documents are at. But what else is there? Is there something I am missing. I am sure we could all get that and just show up to vote for the other guy. But is there something else? He always has some underhanded thing. What else can this bill do to destroy america?

Edit: what about that real ID that he was pushing before. Isnt that the whole point of a real ID to show you are American?