Yes, unvoting is possible, but democracies need dialogue and discussion so discussing about it is even more helpful than downvoting because you can either convince or be convinced or reinforce your ideas that made you either vote or unvote
Yes, unvoting is possible, but democracies need dialogue and discussion so discussing about it is even more helpful than downvoting because you can either convince or be convinced or reinforce your ideas that made you either vote or unvote