iowan who shows up should be offered the chance to register and then to vote, and anyone else should be allowed to observe. but one of the caucus leaders is already laying down the gauntlet saying, and i'm quoting here, we are not just going to tolerate in rural iowa what's going on in the big metropolitan areas. a little thump therapy never hurt anybody. not exactly a quiet coexistence. tensions already getting kind of a little tight over the past week, they expect those to rise tonight, and the cops are vowing to make sure that this thing goes off smoothly across the state, megyn. megyn: yeah. they had predicted that there might be mass arrests, those planning these protests had predicted that. so we shall see. trace, thank you. >> reporter: okay. megyn: also making news to the, new tensions between the u.s. and iran as iran threatens serious fallout if u.s. returns its aircraft carrier to the persian gulf. we're live with the details on that.