land a punch against any particular cappndidate as he di in the previous debate. one aide said he still has some room to improve when it comes to being comfortable. take a listen to a joke bush tried to make last night. go ahead and play that. this vast overreach has created a huge problem for our country, and hillary clinton wants to double down on that. i was in washington, iowa, about three months ago talking about how bad washington, d.c., is. you get kind of the anyway. reporter: so there you see he begins to try to make a joke comparing folks here in iowa to washington, d.c., and he kind of gave up midsentence. one of his aides acknowledged he has some room to grow when it comes to getting more comfortable, but oversaul peoal are satisfied. carol? athena jones in iowa, thank you. still to come, u.s. investigators are about to play a much larger role looking into that crash of that russian airliner. what do they say about the bomb that was planted on board that