Increasingly, Iowans say their caucuses are Ted Cruz's to lose

Some supporters of Senator Marco Rubio of Florida, for example, privately say they believe Mr. Cruz cannot be defeated in Iowa. While those claims may in part be gamesmanship — an attempt to build up Mr. Cruz’s expectations here — more revealing is that neither Mr. Rubio nor the well-financed outside group allied with his campaign has so far spent money on television ads in Iowa assailing Mr. Cruz…

But what gives [Cruz’s] team pause — and what is to many Iowa Republicans the crucial question leading up to Feb. 1 — is whether Mr. Trump will abruptly end his nice-guy routine with Mr. Cruz and begin attacking him in advertisements and behind the microphone at his big, highly publicized rallies.

“I’m a little concerned about that,” Representative Steve King of Iowa, Mr. Cruz’s highest-profile surrogate in the state and travel partner for part of the week, said about the possibility of a Trump offensive. “Trump is so completely unpredictable, we don’t know what he might do campaign-wise. We can’t even begin to think about anticipating that.”