leftist vs oppositionist

leftist

noun
  • A person who holds views associated with the political left. 

  • Someone who holds socialist or communist-leaning economic views, usually alongside progressive social views; an anticapitalist. 

adj
  • Of or pertaining to the political left. 

oppositionist

noun
  • A person who opposes; especially a member of an official opposition 

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