I'm happy for your friends...but they are the exception, not the rule.
There's an old joke that a Conservative is a Liberal who's been mugged and a Liberal is a Conservative who's been indicted. Considering that most felons care about no-one save themselves, I would just as soon prefer that the caliber of Liberals to which the above joke alludes were NOT legal voters.
Felons who've served their complete sentence should have their voting rights restored. They've paid their debt to society and this helps reintegrate them to useful citizenship.