now trump leads the gop field with 18% followed by jeb bush at 15% and scott walker at 10%. and you see the rest of the field of candidates in single digits. jim acosta is "out front" traveling with president obama. it's good to see you. until now president obama hasn't really mentioned trump by name at all. i mean it's pretty significant that he's weighing in right now, right? >> reporter: that's right. it has been almost white house policy to stay clear of the 2016 race especially donald trump. but here in ethiopia president obama jumped right in today, slammed mike huckabee for predicting the iran nuclear deal would lead to a holocaust saying the former arkansas governor was trying to outdo the more sensational donald trump. and then the president wasn't after donald trump for saying john mccain was not a war hero despite being a former p.o.w.