Please do read
Sauvé v. Canada (Chief Electoral Officer), <2002> 3 S.C.R. 519, 2002 SCC 68 -- the decision in which the Supreme Court of Canada (by a narrow margin) struck down the prohibition on voting by inmates in Canadian penitentiaries.
(Canada has never had a rule against people who have been convicted of criminal offences voting if they are not incarcerated. Similar provincial rules have also been struck down.)
http://scc.lexum.umontreal.ca/en/2002/2002scc68/2002scc68.htmlThe decision addresses all rationales for prohibiting people with criminal offences from voting, and offers several very strong arguments for permitting them to vote.
This bit addresses what tends to be the common argument made in the US to support such prohibitions:
43 The idea that certain classes of people are not morally fit or morally worthy to vote and to participate in the law-making process is ancient and obsolete. Edward III pronounced that citizens who committed serious crimes suffered “civil death”, by which a convicted felon was deemed to forfeit all civil rights. Until recently, large classes of people, prisoners among them, were excluded from the franchise. The assumption that they were not fit or “worthy” of voting — whether by reason of class, race, gender or conduct — played a large role in this exclusion. We should reject the retrograde notion that “worthiness” qualifications for voters may be logically viewed as enhancing the political process and respect for the rule of law. As Arbour J.A. stated in Sauvé No. 1, supra, at p. 487, since the adoption of s. 3 of the Charter, it is doubtful “that anyone could now be deprived of the vote on the basis ... that he or she was not decent or responsible”.
44 Denial of the right to vote on the basis of attributed moral unworthiness is inconsistent with the respect for the dignity of every person that lies at the heart of Canadian democracy and the Charter: compare August, supra. It also runs counter to the plain words of s. 3, its exclusion from the s. 33 override, and the idea that laws command obedience because they are made by those whose conduct they govern. For all these reasons, it must, at this stage of our history, be rejected.
It is also worth reading a little more about "civil death", which has been consigned to the ash heap of history in most places now. Wiki has an extremely brief entry that can serve as an introduction:
http://en.wikipedia.org/wiki/Civil_deathCivil death is a term that refers to the loss of all or almost all civil rights by a person due to a conviction for a felony (a crime punishable with more than a year's imprisonment) or due to an act by the government of a country that results in the loss of civil rights. It is usually inflicted on persons convicted of crimes against the state or adults determined by a court to be legally incompetent because of mental disability.
A prominent example of civil death is the "illegal enemy combatant" designation used by the United States government, to avoid due process as described by the United States Constitution and protections for prisoners of war described in the Geneva Conventions. A second example of civil death on a wide scale is the use of purges by the former Soviet Union under Joseph Stalin.
Historically outlawry, that is, declaring a person as an outlaw, was a common form of civil death.
Note the philosophy that one is signing onto in advocating that civil death -- the loss of civil rights, such as voting rights -- be imposed on someone.