> This is left up to the states.

Sure, but almost every state blocks it for the duration of your time in prison, at minimum. A fair portion are longer, and some states make it almost impossible for federal felons to vote.

https://www.brennancenter.org/our-work/research-reports/can-...

> Our current president is a convicted felon.

That’s federal, which has no barriers. It’s left up to the states to decide how state level offices work, and being a convicted felon is a knife in the back of any potential political career. In NY specifically (where Swartz lived) you need a “Certificate of Good Conduct” or else you can’t run, and it would have taken (assuming he got convicted with 7 years as was threatened) 8-13 years for him to be legally able.

The exact specifics don’t even matter for Swartz’s case though, because for him it was more ideological than practical.