While this action may technically be unconstitutional, the Postmaster General is only pushing Congress to act after nearly 15 years of obstruction. In fact, USPS is taking this action as part of a broader cost-saving measure to save the postal service from extinction.
Extreme measures like this wouldn't be necessary if Republicans (and a few corporatist Democrats) in Congress would remove the insane burden they placed on the Postal service with the Orwellian-named 'Postal Accountability and Enhancement Act' - an action that forced the postal service to pre-fund 75 years’ worth of pensions and health care coverage for retirees at a 100% rate, a burden no other public or private institution in America has to match.
If you think any private company anywhere in the world could do what the Postal Service does, for anywhere near the cost they charge, you need to watch this quick movie from Esquire's Jesse Lichtenstein.
Now, read Lichtenstein's full piece, "Do We Really Want to Live Without the Post Office" in Esquire Magazine.
As Lichtenstein says:
This isn't a story about whether we could live without the post office.
It's about whether we'd want to.