Former Democratic presidential nominee John Kerry disliked Cooper's question about friendship to end CNN's debate Tuesday night, along with many other Twitter users. "Twenty years from now, it won't wear well that in a THREE hour debate, there was time to ask about Ellen at a Cowboys game, but not climate change. Not once!" Kerry tweeted. But journalism professor Alan Schroeder, who's written two books titled Presidential Debates, thinks those kinds of questions are needed in a debate. “The idea is to come up with a topic for which the candidates do not have a prepared response, something that throws them off their stump speeches and requires them to respond spontaneously,” Schroeder wrote in an email to The Washington Post. “That would have been the reasoning behind the ‘unexpected friend’ question last night.” He pointed to Donald Trump and Hillary Clinton being asked to "name one positive thing" about each other during the 2016 debates. He also noted that Kerry and Bush were the recipients of a similar question when they were asked about the women in their lives during the 2004 presidential debates. “Sometimes debaters are asked questions that seem to come out of left field but that end up revealing valuable info about the candidates,” sais Schroeder.