beg the question vs cloud the issue

beg the question

verb
  • To sidestep or fail to address a question. 

  • To raise or prompt a question. 

  • To engage in the logical fallacy of begging the question (petitio principii). 

cloud the issue

How often have the words beg the question and cloud the issue occurred in a corpus of books? (source: Google Ngram Viewer )