politician vs usurper

politician

noun
  • A sly or ingratiating person. 

  • Specifically, one who regards elected political office as a career. 

  • One engaged in politics, especially an elected or appointed government official. 

  • A politically active or interested person. 

usurper

noun
  • One who usurps. 

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