leader. >> and that's what he is, he's a gangster. >> reporter: jeb bush, who held his own amid struggling numbers, is targeting donald trump's promise to send syrian refugees home. >> wow. i'm thinking, donald, to their slaughter? is that the america that represents this extraordinary country? >> reporter: division, highlighted in this week's debate, now playing out on the campaign trail. >> and that was nbc's tracie potts reporting for us from washington. a university of missouri student will appear in court this morning, charged with making terroristic threats. amidst all the racial tensions there over the past week, 19-year-old hunter n. park was taken into custody 90 miles south of the school. allegedly posting on social media site yik yak, i'm going to stand my ground tomorrow and shoot every black person i see. adding, don't go to campus tomorrow, and we will kill you. well some students just packed their bags. security was increased on campus.