Ramesh notes how the Rubio attack on Cruz on defense isn’t going to work. It is probably only Trump who can hurt Cruz at this point, and only if he is very serious about doing it. I don’t believe the bizarre attacks on Cruz’s faith are going to work, and although the silly Canadian thing (I loved Jim’s take from The Jolt) could create doubts about Cruz for some voters, that doesn’t strike me as a very telling attack either.
From where Trump sits, the best jibes against Cruz, it seems to me, would be 1) Ted Cruz is afraid of me; 2) Ted Cruz is a political insider; 3) Ted Cruz wants you to believe that he’s like me, but he’s not. Much of this would be an authenticity critique. It may be that Cruz’s brand is too established for any of this to work against him, either. But Cruz clearly worries about the potential damage of broadsides from The Donald, which is why he is constantly deflecting and ducking and covering when it comes to the real-estate mogul.
As for Trump, at some point I’d think he has to realize how important Iowa is. It could make the difference between him winning no states and establishing a commanding position for the nomination within the first 8 days. And at this point, unless an army of new Trump voters is going to swamp the caucuses, he has to go through Ted Cruz to win Iowa.