It has been made in Sierra Leona as a kind of experiment. It was run by a private company called Agora, and the purpose was to determinate if the use of the Blockchain could secure the electoral process.
Read more in here: https://techcrunch.com/2018/03/14/sierra-leone-just-ran-the-first-blockchain-based-election/
Now, from my perspective, actually, the Blockchain technology could even change the way we vote into a more secure system, but some problems need to be solved:
- Mining. Who are going to be the miners? Volunteers? Because if the mining power resides in just an enterprise (Like the Agora case), then it shouldn`t be believed as a fair system.
- How to purchase your vote. Of course, voting can be managed as a Blockchain transaction, but how can anyone be sure that the votes are in fact legit?

Anyway, I do see a future in which elections are going to be based on the Blockchain tech. This is a matter of time that this two tiny problems will be solved. I don`t know, maybe smart contracts have something to say, maybe a new system of electronic voting. But it is coming, I think.