Cruz did not either sense the trap coming from Fox, as Trump, or he thought it was worth the risk. in either case he has been badly damaged. if he does not win Iowa he has serious problems and has allowed Rubio and Bush to rise. He was much better off tacking behind Trump until he could reach the SEC primary states. if he loses Iowa and he cannot win NH his prospects in SC and the SEC except Texas are dim.
After Cruz’s Iowa loss...he will be an after thought.