By committing a crime, felons have shown they are not responsible enough to vote. They have displayed extremely poor moral character, and society does not benefit by then allowing them to vote. Simply serving a government-mandated sentence does not prove that a person is morally responsible. In order to regain their voting rights, felons should have to prove that they deserve this privilege. This might involve performing community service, maintaining a clean criminal record for a certain amount of time, or presenting character references to the State.
There is no moral character requirement for voting. Many members of society may have poor moral character without being convicted of felonies, and their right to vote is never in question. Judging someone by their past actions, which they have paid for in the eyes of the law, is undemocratic. Additionally, there is no proof that every felon has poor moral character. People may be convicted for any number of reasons: due to poverty or self-defence, or even being wrongly convicted. The criminal justice system is not perfect, and should not be used as an excuse to continually disenfranchise felons.
[P1] It is only desirable that citizens with a certain amount of moral character be able to vote. [P2] Felons have not proved they are responsible enough to vote by breaking the law.
Rejecting the premises
[Rejecting P1] There is no 'moral character' test for voting, and to judge felons on this basis is unfair.