I've long wondered what are the constraints on that. Do states inform each other about convicted felons? What if I have a common name, such as Robert Jones, and I register to vote. I am pretty certain that there must be more than one Robert Jones out there who's a convicted felon, maybe even in my state. How do I prove I'm a Robert Jones who has NEVER been in trouble with the law.]
Conversely, what if I'm Robert Jones, convicted felon is a state perhaps on the east coast. I serve my time. I'm now a free man. I move to another state. If I register to vote, how can my new state connect me to the felon I have been.
I'm deliberately using a common name here, because common names are at the heart of a lot of supposed voter fraud.
In my real life I have a name that is extremely uncommon. I, personally, have never been convicted of a felony. But I'm aware of the total bullshit that Republicans claim about voter fraud.
If I were in charge, anyone who is a citizen would be eligible to vote. Even if currently incarcerated.