Artist: M. Abramov, Verse: Sergei Mikhalkov [one of the top Soviet poets in the 1950s-1960s]
The verse in the top left-hand corner reads:
As soon as he was elevated,
His mind has died and ego escalated.
The character leans on the words I AM IRREPLACEABLE.
This poster is directed at arrogant bureaucrats who, after being promoted to higher positions, begin to look down upon people.