contend vs draw a line in the sand

contend

verb
  • contend with: To try to cope with a difficulty or problem. 

  • To be in opposition; to contest; to dispute; to vie; to quarrel; to fight. 

  • To be in debate; to engage in discussion; to dispute; to argue. 

  • To believe (something is reasonable) and argue (for it); to advocate. 

  • To struggle or exert oneself to obtain or retain possession of, or to defend. 

draw a line in the sand

verb
  • To lay down a challenge; to provide a test of commitment (often one which carries a high risk) to a cause. 

  • To create a real or artificial boundary or distinction between (two places, people or things). 

  • To indicate the threshold or level above which something will become unacceptable or will provoke a response; to create a boundary and imply or declare that its crossing will provoke a (negative) response. 

How often have the words contend and draw a line in the sand occurred in a corpus of books? (source: Google Ngram Viewer )