Of course people in jail should be allowed to vote. I hate the whole idea that people in jail are all dirty, bad people. They made a bad mistake, but that should not define their entire being. They're still mothers and fathers, daughters and sons. Sure, of course there's some people in jail who have killed or raped others and have no good excuse for these actions. But maybe one of those rapists was sexually abused by his father for his whole life, lived a life in social isolation and emotional abuse, and so raping is the only thing he knows. Or maybe one of those people in jail got caught with a large amount of drugs, because they were desperately trying to fit in with a new group of friends after being teased their whole lives because of their weight. Or maybe another one of those people in jail is a woman who finally beat up her husband after suffering his abuse for too long, or a single mother who stole food from a grocery store to feed her children because she couldn't afford to buy it.
I'm not trying to justify the actions that people have taken, but my point is - people in jail are still people. They may not be as different from you than you think. And so, of course, they should not lose one of the most basic human rights.
I mean, I've broken the law too - speeding, underage drinking, I even stole a lipstick from a convenience store once when I was 11 haha. But just because people make bad choices sometimes, it doesn't make them inherently bad or less deserving of human rights.