There is no power to be exercised in this scenario. They can vote, but it is literally mere coincidence if anything related to their intentions occurs. It’s like typing onto a keyboard that isn’t plugged in. Or prayers to a non-existent deity. Voting ceases having anything to do with reality the moment reality stops having anything to do with the decision behind the vote. It is action without a discernible causal connection to the result.

(Is it just me, or does our disagreement sound like two people arguing if a tree falling alone in a forest makes a noise, because one thinks “noise” is the vibration and the other thinks it is the qualia?)