CNN's moderators asked two questions during the Democratic primary debate on the issue of racial justice in America, but the topic was noticeably absent during the network's Republican primary debate.

During CNN's October 13 Democratic primary debate, moderator Anderson Cooper turned to Don Lemon, in order to “talk about issues of race in America.” Lemon introduced a video question submitted via Facebook that asked, “Do black lives matter or do all lives matter?” Lemon noted that the question has previously been a stumbling block for some of the candidates on stage, and Cooper followed up by asking Secretary Hillary Clinton, “What would you do for African Americans in this country that President Obama couldn't?” The candidates' responses focused on institutional racism and urged reform on criminal justice, policing, education, jobs, and housing. In total, the debate dedicated nearly five minutes to discussing racial justice.

In contrast, CNN's September 16 Republican primary debate did not include a single question on racial justice.

The absence of questions addressing racial relations didn't go unnoticed. New York Times columnist Charles M. Blow wrote that “it was both fascinating and disappointing that race relations in America were not directly addressed” during the Republican debate despite the fact that “issues of race consume the news,” and polls show it is among the top three most important issues facing the country.

Following the Democratic debate, Huffington Post reported that race was one of several issues Democrats discussed in their CNN presidential primary debate that Republicans didn't, writing “the GOP contenders, however, have failed to utter the word 'black' even once during either of their debates.”

Media Matters compiled a list detailing the amount of time spent during the CNN Republican and Democratic debates on various topics:

Methodology: Media Matters counted the time spent discussing each topic, counting from the beginning of the moderator's question on a given topic to the end of the last candidate's response on that topic. The time count only includes questions that were focused on the above topics and the responses given, it does not include discussions of those issues during opening and closing statements or responses addressing those issues during questions focused on other topics.

Julie Alderman, Cydney Hargis, and Brendan Karet contributed research to this post