In California they're suing to allow it, for cases of non-violent felons serving time in county jails, after the court ruled the prisons were over populated and they had to start moving non violent non sexual felons to county jails... these aren't people who 'did their time' either.

Also there are numerous groups claiming that because more blacks are imprison, denying felons there right to vote is racist, some of these mean after they're out, some are actually talking about in prison. So yeah, there are people doing this.

I think most of us believe there should be some route for felons to be able to vote down the road (and most states have this) IIRC Texas lets them vote immediately after release, Florida is getting hit right now over claims of racism for wanting to have it be five years. I think the norm is someone can vote again for non-violent as soon as they are out of prison and off parole but it varies a lot. In Ohio, you can apply to get your vote back right away out of prison for State offenses, but not Federal, IIRC.