I think that a fundamental dynamic that may be being overlooked, aside from the costs mentioned above is that to approach this from the only right that is denied a felon is somewhat flawed. Yes, it may be a "right" that is is ultimately not allowed to resume when the felon is released. But of all the rights that are suspended upon conviction, one could argue, that this is the only one that is controversial. A politician would/and probably did make a case for the return of the right to vote. No politician would sponsor a "guns for felons" campaign. Of all the rights limited in some way by a felony conviction including voting, holding public office, jury service, witnessing documents, immigration and military service, federal contract exclusion, one could argue bearing arms certainly is not particularly analogous to these, at least in terms of underlying policy today and as such this is not an appropriate metric to determine if it is a right.

This is as another poster mentioned a function of money and politics.