The official stance is that it is strongly suggested that you do not vote.
If an unbelieving husband forces his wife to go with him to the
polling booth she is expected to cast a vote for God's Kingdom or
do nothing and turn in a blank sheet of paper.
The Witnesses are more critical of voting now than they were
10 years ago. Voting is almost as taboo as taking blood. If you vote
I don't think that they would officially disfellowship you for that
because in today's political climate that would be bad PR if it
became public knowledge.
Sour Grapes