"Close the deal" is usually used for candidates polling in first.
If Cruz doesn't finish first in Iowa, he may as well drop out on February 2. With his "most-effect" ads, alleged best ground game, and in a state that's tailor-made for him... if he can't win in Iowa, where, exactly, can Cruz win, that's not maybe his home state?
I think once stuff like this (see below) truly gets out there, Trump will be such a laughing stock that Cruz will slide into first without too much trouble...especially in states that don’t appreciate Donald Trump’s leftist NYC values. Can you imagine all the stuff they left out that they could have put in? You can bet they are saving the rest for later, should Ducking Donald make it to the general...
http://www.freerepublic.com/focus/f-news/3390733/posts