I don't think we should start from the conclusion of prohibiting AI from voting. We should come up for the criteria for voting and allow anything that meets those criteria vote.

Normally I would say it can be solved by the "shareholder" / "landholder" model. However technically, a sentient AI could own wealth / land. 

Voting rights may need to be restricted to "a corporal shareholder". 

freetx

AskSN

Should true AI have rights?

Aardvark

My view is that all rights are property rights. Voting is privilege, not a right, but we will likely have to refine how one qualifies for that privilege, unless we can abolish the state in the near future.