I wasn't referring specifically to juries. The ranges of punishments that are prescribed for crimes are done so by democratically elected legislatures in most modern nations, including the US, though judges and juries do have varying degrees of discretion in the matter.

My main point is that in a democracy one shouldn't take the law that exists in a particular place and time as some absolute that cannot be questioned because those laws can and do change through political action, as has recently been happening with drug laws and mandatory sentences for drug crimes.