Earlier quoted context omitted.
The First Amendment doesn't mention anything about secrets, that's not what this is about. If I sell you a stolen item, and you know it is stolen , you're guilty of a crime. If you later try to sell or move those goods, that's a more severe crime, fencing. In this case the reporter is obtaining "stolen" information and passing it along, it's exactly the "fencing" of information. I'm aware this practice has been going…
Normal citizens have no obligation to keep the secrets of any government organisation. It is the person who holds security clearance that leaks the document that commits a crime, whereas journalists have a constitutionally protected right to publish. It's not sleazy, and is part of a healthy system that holds governments to account.
When leaked classified documents show something highly troubling, like the Snowden leaks or Wikileaks, the government doubles down and does everything it can to punish those leakers to the maximum extent, which is not what a "healthy system" would do to a whistleblower exposing illegal or corrupt activity.