cajoler vs smooth operator

cajoler

noun
  • A person who cajoles; a flatterer. 

  • A speech act intended to persuade or convince, such as the utterance "you know". 

smooth operator

noun
  • A skillful, manipulative person, con artist, or clever scoundrel. 

  • A person who accomplishes tasks with efficiency and grace, especially one with verbal skills who is persuasive in interpersonal relationships, negotiation, etc. 

How often have the words cajoler and smooth operator occurred in a corpus of books? (source: Google Ngram Viewer )