The people who should not have their voting rights returned are people guilty of things like bribing politicians or other similar corruption, high level economic crime, organised crime, international crime, as a statement of them having betrayed society. No, I do not have any ideas for how to turn this moral judgement into actual realistic policy. It's just what I see is just.
Crimes involving (by a given standard, edge cases may need to be established) voting/representation are disqualifying events for life?
Bank robbery, pickpocketing (even of a politician), tax evasion/fraud/insider-trading (
without a political dimension, e.g. abuse of an office) do not affect voting upon finally serving your tariff/gaining parole, where applicable.
One might wonder whether illegal trespass on government property or riotous behaviour at a protest might count (I'd say not, instinctively) but that might be where the consideration (or allowance of discretion/punitism, given 1st Amendment stuff, etc) would need to be focussed if/when implemented.
(Yes, voliol, there's room to mess with people's encranchisement, but only
if there's quite obvious "this mugging prevented the victim from voting", "this burglary took that household's ballot papers", "this aftempt to blackmail an Ex wth intimate photos was to force them to vote differently" Every Single Time someone gets convicted of <whatever> and fits with the targetted suppression demographic. If it'scommon enough to be worthwhile, it'd be blindingly obvious to the average court-reporter, and thus the public. Or so maybe I naïvely imagine.)
((If you mean increased criminalisation/imprisonment for suppression
during the time of incarceration, which is something maybe that is easier to imagine as part of "removed from society" punishment, unless you grant them the ability to absentee vote/set up ballet booths in the institution, then that's what's badically happening now, and then
not getting the vote back upon release.))
As an interesting equivalence, if you are imprisoned in the UK you are not liable to pay Council Tax (local authority taxation)
unless you are in prison for not paying your Council Tax... (Typically that would be due to refusal, rather than inability, which can be more leniently dealt with. So the point is that you don't 'get away with' the time you spend inside.)
(((Ninjas shouldn' be allowed to vote!)))