As Charlie noted, Cruz was caught describing at a fundraiser what is obviously an element of his primary strategy — to kill Carson and Trump by kindness. This strategy makes perfect sense. With Carson, why antagonize the doctor’s supporters when he’s likely to fade anyway? With Trump, the same calculation is at work, plus an added incentive — criticizing Trump risks a nuclear response that could, depending on how it plays, be quite damaging. So Cruz tap-danced around his remarks at the fundraiser when they came to light, and when Trump slapped at him on Twitter, Cruz responded by saying how terrific Trump is. An important question here is what matters more to Trump: the fact of the (transparently insincere) gestures of submissiveness from Cruz, or the purpose of the (transparently insincere) gestures of submissiveness from Cruz, namely to tip-toe around Trump in Iowa? Trump has now hit at Cruz again (although not very effectively), an indication that the answer may be the latter.