In 2006, the outgoing congress enacted and president G W Bush signed the Postal Accountability and Enhancement Act. There is a clause requiring the Post Office to pre-fund, within 10 years, 75 years of employee retirement and health care. They're required to do this without passing on the costs to postal customers. It's a poison pill. An attempt by republicans and more importantly corporate lobbyists to privatize the Post Office. The USPS is one of the largest union shops in the country. If they can bust this up, they can wipe out much of the union support of the Democratic Party in future elections. This is also, I believe the largest employer of veterans in the US.