Why should Prisoners be Denied the Vote ?

I think I might be alone on this one, but I think prisoners SHOULD be allowed to vote.

Deep down within me it just does not seem right that we have a society that locks people up and then stops them from any participation in the democratic method of choosing how our society is run. I'm sure that how despots and dictators behave i.e. lock up your opponents.

I'm being a bit extreme but what are risks to our society by allowing 80,000 extra people exercise their vote, Will society crumble ? or would allowing prisoners to engage in the vote perhaps add to the chances of a prisoner rehabilitating and become more aware of how a society operates.

Prison is for 2 things, safety of the public and punishment. Is loss of liberty not enough punishment ? Does removing the vote add anything to the severity of punishment ?

Removing the vote from prisoners simply distances them from the rest of us and does nothing to prevent any of us from being a victim of crime.