developing tonight, wear still waiting to hear of the man killed during a stabbing in they arrested donny mathis for the death yesterday. he first pushed the woman on nebraska avenue friday night, then got into a fight with a man she was with, stabbing him with a knife. a witness tells us detectives tried to wash the blood off the knife. mathis is now facing second degree murder. >>> and now to democracy 2016. it was a super bowl sunday on the campaign trail. >> that meant cashing in on last night's debate or making up for lost ground. and for marco rubio, he finds himself in defense mode. marcy gonzalez explains. >> reporter: a tamer on the trail -- >> 100 miles to eat breakfast with you. >> wow! >> reporter: -- following a fiery night on the gop stage. >> let me talk -- >> quiet. >> -- a lot of times -- >> reporter: donald trump moving up even more in the polls today, standing by some of his most controversial >> so as president you would authorize torture? >> yes, i would absolutely authorize something beyond water boarding. >> reporter: to be more like him? >> yes, i'm sorry. you have to do