hot potato vs political football

hot potato

noun
  • An awkward or delicate problem with which nobody wants to be associated. 

  • A child's game in which players pass a ball or other item between them, with the object of avoiding being left holding the item when time expires. 

political football

noun
  • Ongoing unproductive wrangling or posturing between political factions, resulting in failure to deal with an issue or problem in a decisive or appropriate way. 

  • A contentious political issue or problem that is often debated or discussed, but that remains unresolved; an issue or problem which is avoided by authorities and handed off to others. 

How often have the words hot potato and political football occurred in a corpus of books? (source: Google Ngram Viewer )