power supporting iraqi ground forces as they support isis. >> it's about momentum, cutting off raqqa from mosul. >> why cutting a supply line could drive the terrorists out. also -- two students in missouri held by cops for allegingly making threats against black students. >> i'm so upset right now. >> somber. >> just tense. it's really tense. >> boy cotts, resignations, and the protests now spreading to campuses beyond mizzou. plus -- >> can senator rubio beat secretary clinton? >> i'm a better bet. >> the gop candidates zero in on another candidate. marco rubio. he speaks in south carolina. will he fire back? let's talk live in the "cnn newsroom." and good morning, i'm carol costello. thank you for joining me. we are following breaking news on what is called a major offensive in the war on isis. kurdish forces backed by