It’s a caucus, not a primary. They are two entirely different things. Cruz has people in EVERY county in Iowa and the three other early voting states.
I’ve heard it said several times that Trump is in all Iowa counties and has one of the best Iowa ops going. These aren’t Trump folks saying that. Of course, I don’t live there and don’t know one way or the other, it’s just what is reported.
Same for getting registered in this or that state. Trump easily beats the registration deadline and the number of signatures needed.
I’m not surprised by that. Trump hires someone to make sure he (Trump) is doing what needs to be done in each state and that person deals with it. Loser campaigns have problems dealing with the many routine requirements, primarily due to lack of money.
Walker was intent on doing well in Iowa and he was until he and the other candidates got Trumped. Walker’s polling and thus his funding stream collapsed and all the funds he had spent in Iowa went for naught.