It's odd that the USA, which champions democracy, doesn't hold the right to vote as a universal and inalienable right of all citizens.
Wikipedia actually has an interesting map on the subject for the US (below the fold/ToC):
Unfortunately, some states (including the United Kindom) wilfully defy the ECtHR on this issue.
But I also don't think it's unreasonable to allow some prisoners to vote, especially where they are imprisoned for short sentences and where it is in the interests of rehabilitating them to do so.
It's not like stabbing someone makes your opinion on taxes less valid. Or drug dealing makes your opinion of the education system invalid.
Even if you rob someone, your opinion that the poor (a.k.a. probably you) should be financially supported by the government is not less valid.
There can a point be made that you're not exactly participating in society while you're in prison, so if we act like politics always perfectly reflect people's current needs and don't cumbersomely shape over decades, then you could argue that they shouldn't be allowed to vote over other people's society, therefore should only be allowed to vote when they're going to be released in the next legislature period. But that's just not the case. A moron in presidency can and will negatively affect people's lives for a long time after he's gone.
Lastly, I suppose, if you view prison primarily as punishment, then taking away their right to vote just extends that.
Nothing basic about it. The "War on Drugs", as we know it today, was literally started by the Nixon administration as a means to control liberals and minorities.[0]
0 - https://harpers.org/archive/2016/04/legalize-it-all/ (the money quote, by Ehrlichman, is in the second paragraph)
I have always thought that was outrageous. I think people should be aloud to vote even while they're in jail. The current system could allow a group to wipe out their political opponents by simply passing a law outlawing a common activity, then selectively enforcing it. I mean that's basically what the war on drugs was about.