It does not appear that Biden* has gained brownie points with the Postal Workers' Union.
...The 220,000 members of the American Postal Workers Union (APWU) released a statement saying the federal government has no business attempting to force vaccinate the workforce. This union will not be the only one…
It's a "working conditions" matter, covered by contract. There are lots of other Federal unions--Treasury Workers' comes to mind, e.g.