Only if a referendum contradicts the letter or the spirit of the Constitution. For example, a referendum would have no authority to deny people their right to own a gun.
Forgive me if I am being obtuse, I am trying to understand:
If the state legislature elects to divide their electoral votes in the manner described herein, as is their right, would you still object to this? Is it simply the idea of using a referendum to do so that bothers you, or do you require that the state leave it's electoral votes whole?