Lookups spiked on August 28, 2013.
There are probably a few reasons why rhetoric spiked this week: It was connected with two major new stories - the crisis in Syria and the 50th anniversary of the "I Have a Dream" speech by Martin Luther King, Jr. - and it's also a word that increases in lookups every year when students return to class.
In a political context, rhetoric can mean "insincere or grandiloquent language," as in:
"The current face-off between the U.S. and Syria is the product of blurred rhetoric, diplomatic double talk, and shocking miscalculations from both sides." - Barry Lando, Huffington Post, August 29, 2013
Referring to a stirring speech, rhetoric means "skill in the effective use of speech," as in:
"Between Obama, Clinton and Carter, none delivered the magisterial rhetoric of the "I Have a Dream" speech." - Mike Kelly, The Record, August 28, 2013
Finally, in classrooms, it generally means "the study of writing or speaking as a means of communication or persuasion."
Rhetoric comes from the Greek word meaning "art of oratory."