I'm a Guardian reading Brit, quasi liberal with a touch of Tory. So take my comments with a pinch of salt as you have focused on a US perspective ...
Should convicted felons get to vote while in prison, after serving their term or ever?
Personally ...No they should not be able to vote, I believe you should pay a price for your crimes. Your freedom is being stripped from you for a reason.
From a really lazy google I have found a link
about the debate going on with UK/Europe over this very matter. While it worries me that I agree with Cameron, I do.
Could the prison vote make a difference in an election - locally, or at federal or state level?
Depends if you live beside a HUGE prison? Personally I'd be more worried about the general population makeup in the area you live in.
Do you think a politician would ever pander to the prisoners ...perhaps while covertly trying to change laws to allow them to vote?
I've never yet seen a politician who will not pander to someone/something/someTVshow for a vote. We have some shockers in the UK, but ... I will never assume for the US ... you nearly had Palin as VP
But .. saying that .. the Politician would need to be in an area with a HUGE prison to pander to the inmates ...
What kind of leader do you think the general felon population would support, or perhaps the group is too diverse to categorize??
I cannot possibly say, I do not hang about with prisoners but I would assume they are a rich and a varied bunch.
Edit: Another question, what's a wild estimated of the percentage of felons that would bother voting even if they could?
Those who gave a **** will. I bet those are also the ones who make it back into mainstream society.