What you’re not understanding is that SCOTUS has no power to demand that any entity legislate anything at all.
Congress and state legislatures have the legitimate right to ignore the SCOTUS.
This is why we need Cruz, and no one else.
The rest, Trump included, are orders of magnitude below him.
Sounds like you may have the process a bit discombobulated.
Back to Constitution 101 for you.
Yes, hopefully Cruz will be the nominee if Trump stumbles or more likely decides he has had enough playing Pied Piper, looks around and points to Cruz to finish the deal.