I think the reason their voting rights were taken away was because they might vote in "felon friendly" laws, and when you think about it, there are a lot of felons...So if the numbers added up...Welllll, they could "rock the vote" so to speak.

I'm not really sure...But I think I'd say only after they served their time in full and then 10 years, and then voting right should be restored.
Because 10 years is enough time, I think, to pull yourself out of the gutter, and into something better, or to get sent back to jail.