Only after it was evident that wasn't happening did he go on offense against the front-runner. He got slapped down rather handily, and now there's not much time to battle back.
I gotta say, I didn't predict Cruz going the way of Ben Carson in this race in Iowa, until that last debate. That NY Values attack, and Trump's incredible response, was the beginning of the end.
It was definitely a Hail Mary last attempt at taking Trump. Cruz’s camp were caught flat-footed by the NBC issue, but they had a sliver of a chance to rebound. The “NY Values” comment was the bad turn that allowed Trump to land the lucky broadside.
After that Cruz’s ship was paralyzed. Then the Palin endorsement was another devastating direct hit, the National Review fiasco was like being hit with friendly fire, and Beck was the gun powder below deck exploding a hole in the side. The ship was now sunk.