This ain’t Ben Franklin’s post office.
https://about.usps.com/who-we-are/postal-facts/size-scope.htm
According to their own data, they have ~617,254 employees, and they pay out $1.8 billion every two weeks in salary and benefits. Although I'm sure it's an inadequate calculation that is missing some significant variables, this appears to come out to something like $75,820/year per employee in salary and benefits. I'm sure there are many hard working people among those 617,254, including some hardworking people I know. The question is, how sustainable is this, and what can be done to make it sustainable if it isn't.
Again, simple calculations, but at $1.8 billion of salary and wages every two weeks, the annual salary and benefits expenses would appear to be ~46.8 billion. They list an annual revenue (from 2014) of $67.8 billion, thus ~69% of their total annual revenue goes to salary and benefits. There is also a $5.7 billion annual pre-fund for future retirees they are mandated to pay by Congress. I don't know if this is included in the above, but if not it obviously brings their personnel costs well into the 70th percentile of their total revenues. They had a deficit of $5.5 billion for 2014. This is from their own math and figures, so it could even be worse if there are deficits etc. that are not being included.
One very big question is how was it allowed to get to this point? It's the same kick the can down the road mentality that has gotten the US into trouble in multiple other areas, and it would appear that this union would like to vote for the candidate most likely to continue taking that approach.