The reason for the refer to the feds is that the courts have ruled that only the Feds can enforce immigration laws (i.e. deport). Authorizing and empowering local LEO to deport would be a huge game changer.
It would have to go beyond the LEOs. Someone has to handle the detention, deportation hearing and actual deportation. LEOs can arrest, but you would need a whole new state bureaucracy to handle it. Which isn’t necessary if the Feds just do their job and cooperate with the states to enforce the law.