This comes up every month or so, and it's always people saying the same things, many of which are extremely poorly thought out. I am going to try to elaborate my thoughts without any unkindness.
No, felons should not be able to own firearms. I think there are caveats to that - that felons should be able to go through a fair process to regain their rights, including firearms ownership and voting, but that it should not be automatic or easy (but should not be substantially burdensome from a financial standpoint) and should be contingent on law-abiding behavior post-release for a duration of time commensurate to the offense committed similar to how conviction history and severity plays into sentencing guidelines now. I also think that fewer things should be felonies or federal crimes.
Q: Most felons are just victims of the administrative bureaucratic state/nonviolent offenders/in prison for being caught with a joint!
A: This is demonstrably untrue. The US has about 2 million people incarcerated for one reason or another, more than half of which are in state prisons, since this is where most criminal convictions end up. Of those 2 million people, the overwhelming plurality and biggest single category of inmates or arrestees (about 800,000), are in jail or prison because they were convicted of or are pending disposition for violent criminal charges. Of the 300,000-some peole who are in jail or prison for drug charges, most are in jail or prison for sale or distribution, and of those who are in jail for possession, many are in local jails pending case disposition and conviction, not because they were sentenced to jail. There are about as many people in custody for property crimes as for drugs.
America is, frankly, for a first-world nation, simply a violent country by comparison. There are a lot of reasons for this, many of which are cultural and demographic, and it can't be boiled down to having too many or too few guns. Really guns are a nonissue.
Q: If a felon has served his time, he's paid his debt to society and should have all his rights back.
A: Roughly 70% of convicts are rearrested within five years of release. Whether a convict who has completed his sentence has 'paid his debt to society' is a matter of opinion, but I would venture that the justice system is not a mathematical equation. Going to prison is meant to punish the convict, hopefully to reform him, and to protect innocent people from the convict by removing him from free society for a period of time. It is not like an accounting balance sheet, where you can just add enough black ink to cancel out the red ink and then you're good. No imprisonment or fine is going to restore the injury suffered by the victim. Further, recidivism rates only count re-arrest rates - there is no way to know for sure how many crimes someone commits before they actually get arrested, but I think it's a safe bet to say that most criminals have committed multiple crimes before they actually go to prison for one. So limiting some of their civil rights after release is largely a matter of risk management for a population that is highly likely to reoffend, and this is not subjective, it is born out by data.
Q: If a felon can't be trusted with a gun after he's released, he shouldn't be released in the first place.
A: There are two issues with this statement. The first is practical, the second is legal. On the first, it is simply not practical to keep all violent criminals incarcerated until we can be sure they won't reoffend - there are not enough jails or enough funding. Further, the bigger practical issue is that there's no way to know with any reliability whether a felon is going to reoffend. How can you determine whether a convict can be 'trusted' after release? Who judges that?
The second issue is a matter of constitutional justice. Far too many people on gun boards are Second Amendment absolutists in the worst way. What I mean by that is not that they believe in the literal and strict textual interpretation of the Second Amendment, or that gun control laws are all unconstitutional. What I mean by that is that a certain breed of Second Amendment absolutists only seem to know or care about the Second Amendment as though that was the only sentence in the Constitution or the Bill of Rights. Most of the Bill of Rights has nothing to do with law-abiding citizens - most of it has to do with the rights of people accused of crimes to substantive and procedural due process of law. And these amendments are no less important to the maintenance of a free country than the Second or First amendments.
The relevant amendment here is the Eighth Amendment right to not be subject to excessive bail or fines or cruel and unusual punishment. How do advocates of the position of keeping prisoners incarcerated indefinitely square indefinite detention of American citizens for any crime until they have been arbitrarily deemed trustworthy with the Eighth Amendment? No one has been able to explain this to me, and I think it's because they don't care about it because the Second Amendment affects them as law-abiding citizens, and they don't think the Eighth Amendment will affect them personally. This is exactly the same mental attitude that casually anti-gun people hold when they support gun control out of a vague sense that it must do some good and because they do not personally incur any of the burdens of that policy.
Right now the simple fact is that we, in the balancing interest of procedural justice, have to release people from prison for (good) legal and (unavoidable) practical reasons even when we are quite confident they're just going to reoffend.
Q: Felons can just get guns illegally, anyway.
A: This is true, but what is also true is that it's easier for them to get guns if there are no legal restrictions on their ability to do it. Making it illegal for felons to own and purchase firearms makes it harder for them to get by forcing them to chase a more limited supply of illegal guns and by providing law enforcement the possibility to convict felons for being in possession of a gun without also requiring them to have victimized someone with it.