Jailed felons are subject to the laws of the land, but have no say in what those laws are. I think that's unjust.
It's especially nefarious when you consider all the people in jail for non-violent offenses.
In the past, felons were transported. It was cruel and caused unspeakable suffering. Kind of like what the felons did. So a balance of a sort.
I've got the strange feeling that Mars may not be the rich person's paradise folks joke about. It may be a prison colony. The rigors of the trip (permanent physical impairment) may preclude soft rich people from applying for the trip.
Anyway, to return to the topic, if I were officiating a baseball game and somebody came out on the field and broke the bat, pried up the bases and tossed the ball over the fence, I'd evict them from the park. It's only sensible. They can't obey the rules, they're out. Otherwise the game is completely disrupted.
Imprisonment is meant for rehabilitation in addition to punishment. There’s the idea, at least in theory, that people who commit crimes can eventually be functional members of society with full rights given a second chance. So we send people to prison and then let them resume their lives as citizens afterwards. If they owe money due to a civil suit they can still vote because why wouldn’t they? Franchise isn’t tied to financial means and shouldn’t be.
Society is not a game or stadium. There is no outside.
Justice is imperfect.
Laws are not all as obvious as 'breaking the bat'.
Now, responding to the part of your comment that isn't the shitty, specious analogy. You beg the question, saying that felons don't get to vote because they've opted out of civilized intercourse. You don't bother to argue the antecedent, you just assume it. That doesn't address the question being asked in the thread, it just affirms the way things are.
Don't forget the third big part: stopping them from violating the rights of others.
They do temporarily lose some rights, they do (and should) get them back when their "debt to society" is paid (which I find a slightly weird term, but whatever), why shouldn't the right to vote be one of the rights that you get back when you're rehabilitated and reintroduced into society, just like your right to freely move about?
Not all felons, though. Only the ones we choose to surveill and prosecute. So coke-sniffing bankers tend never to be caught. But 19 year old poor hispanic kids with weed in their pockets end up in jail on a three strikes violation because the police stop them all the time just for standing on the street.
> if I were officiating a baseball game
Now extend this analogy appropriately: what if the RULES of the baseball game were only written by the winning team? And that team made it so they were allowed to do this stuff without penalty? So they always win.
And the loser team can't fix that. Because to change the rules to make them fair they have to win, and they can't. Because of the rules.
That's how this works in reality: the point to disenfranchising felons isn't to punish them, it's to keep them from voting for the party whose policies might make them less likely to be felons.