political science vs smoke-filled room

political science

noun
  • The systematic study of government and politics. 

  • The analytical study of public policy and policies, past, present, and prospective. 

smoke-filled room

noun
  • A place where powerful people meet to decide a matter in secret, often of a political nature. 

  • Used other than figuratively or idiomatically: see smoke, filled, room. 

How often have the words political science and smoke-filled room occurred in a corpus of books? (source: Google Ngram Viewer )