The only vote they should have is on whether they want their prison term arbitrarily extended or not.
Citizenship is a very precious status AND a citizen’s right to vote is at the basis of citizenship itself!!
If citizens have to share this right with convicted criminals, how better to devalue and dishonor citizenship AND the country? What better way to send a message to criminals that it’s OK to break the law, you will be just like, just as good everyone else who OBSERVES the law?