The Republican mantra has been let’s get activist judges out of the court and it has been difficult to argue against that point. Judges interpret and rule on laws, the legislature makes laws.
So, one might react with great shock, awe and horror that a Republican legislature and Governor has passed and signed a law they know to be illegal in the hopes that an activist judge will overturn settled law.
Governor Rounds cites Brown v The Board of Education as an example of how and why this sort of action has been taken in the past. Of course this is ironic given most Republicans favored segregation.