In any number of ways,
none of which are spelled out in the Constitution. The only thing the Constitution says about punishment is:
- that it can't happen without due process (5th amendment) and that it can't be "cruel and unusual" (8th amendment). Note how in both cases, the wording restricts what the govt can do (in order to protect our rights).
- Congress has the right to punish counterfeiters, pirates, and traitors (section 8).
I don't understand why you're not comprehending my point.
The fifth says that a man cannot be deprived of life, liberty or property without a fair trial. I agree with you that it doesn't say "if a man has undergone due process then he
must be deprived of life, liberty and property", because that would be silly.
If it is the law of the land that a man may be imprisoned for burglery, then he must undergo the due process of law before he can be legally imprisoned - same goes for him being fined or executed,
if and only if that is an established law of the land.
Now, if a man is convicted of murder and the judge rules that he should be executed for his crime, if the prisoner were to then for some reason jump up and say "You can't do that!" the judge can turn around and show him a copy of the fifth amendment where it says "a man cannot be deprived of life, liberty or property without due process of law".
The judge can ask the convicted "Have you been through the due process?" the answer would be yes. He can then ask if capital punishment is a legal punishment, the answer again would be yes.
Therefore the judge can bang his gavel and send the condemned man away.
Why? Because the judge has satisfied the criteria set out in the fifth amendment to protect your rights, he hasn't denied the murderer a fair trial, he hasn't shot the murderer in his cell before trial, he's allowed the man to go through the whole legal process. The restriction imposed by the fifth is thus lifted. He's had his due process and because it's legal, and from the judge's POV fitting to do so, he's been sentenced to execution.
So, to sum up, the Fifth does not explicitly say that your govt has the right to execute citizens. What it does is place a restriction on an
already established legal punishment, which when lifted, allows that already established legal punishment to proceed.
Which is tantamount in all ways but semantics to saying "a man may not be deprived of life, liberty or property without due process of law -
should such due process of law be satisfied, this restriction is lifted and so a man may be deprived of life, liberty or property if that is the decision of the court and such punishments are legal."
If you can't see that, I'm afraid I must give up.