allegation vs hit piece

allegation

noun
  • An assertion, especially an accusation, not necessarily based on facts. 

  • The act of alleging. 

hit piece

noun
  • A published article or post aiming to sway public opinion by presenting false or biased information in a way that appears objective and truthful. 

How often have the words allegation and hit piece occurred in a corpus of books? (source: Google Ngram Viewer )