slam piece vs smear campaign

slam piece

noun
  • A journalistic or other treatment which portrays its subject in a highly unfavorable manner. 

  • A sexual partner to whom one has no particular emotional attachment. 

smear campaign

noun
  • An effort to damage or call into question someone's reputation, by propounding negative propaganda. 

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