“Isn’t this up to the party? It is a private entity - I don’t see how the courts have any jurisdiction over this.”
I believe the ruling essentially said as much. All it said was that state law could not force the delegates to vote a certain way, but it did not speak to RNC rules. In other words, what really matters is what the rules committee — and possibly the entire 2400+ member delegation if they get a minority report out of committee — says about the issue.
But wasn’t that decided in the 2012 convention? Aren’t those rules what people who signed up to run for president agreed to be governed by?