Cactus Jack Garner once told Lyndon Johnson that the vice-presidency "wasn't worth a bucket of warm spit," because "the Vice President is just a waiting boy, waiting just in case something happens to the President."
In this case, I think it applies to both of those at the top of the executive branch. (And Cactus Jack didn't actually use the word "spit" either.)
Spit, at least, has some life giving, redeemable properties.