captioning sponsored by newshour productions, llc >> ifill: good evening. i'm gwen ifill. >> woodruff: and i'm judy woodruff . >> ifill: on the newshour tonight: countdown to the new hampshire primary. we hear the candidate's final pitches a day before voting. >> woodruff: also ahead: why nato and the u.s. plan on beefing up military forces against russia. >> ifill: and miles o'brien on the ground in brazil, the center of the zika virus outbreak. >> trying to solve the medical problem won't be enough. you have to change the quality of people's life. otherwise, you will not solve this problem. >> woodruff: all that and more on tonight's pbs newshour.