Skip to 1:20 below for the key bit. If you’ve been waiting for Cruz to hammer the point that Trump is erratic and potentially dangerous as president, a fear that seemed to have resonance in Iowa, here it is in spades. That’s a smart way to appeal to undecideds, I think, even more so than attacking Trump’s conservative heresies because unpredictability is a quality that most voters naturally disdain in someone running for the world’s most powerful job. Even if you’re at peace with Trump deviating here and there from Reagan orthodoxy, chances are you’re not thrilled at the thought of presidential tweetstorms whenever he doesn’t get his way on something. Rich Lowry rightly praises Cruz here for deftly weaving mockery and substantive criticism of Trump’s record together, which is true, but I’m surprised that Cruz doesn’t emphasize what Trump’s loss in Iowa says about his managerial acumen. That’s the way to kill Trump — not by calling him a RINO, which many of his fans don’t care about, but by using Iowa as proof that the Great and Powerful Oz wasn’t so great and powerful when it counted. If America’s going to do so much winning under Trump that we all get bored with winning, how come the winning didn’t start in Iowa?

If you think the Trump/Cruz war is fun, wait until the Palin/Cruz war heats up. There’s probably no advantage to Cruz in engaging there, but Palin’s doing her best to bait him. Meanwhile, as Trump and his surrogates go kitchen-sink on Cruz and suck up all the available media oxygen, the Christie/Bush/Kasich triad that’s trying to take down Rubio is gasping for air. Someone’s going to need to explain to me later why Trump is bombing Cruz this week instead of the guy who’s piling up endorsements and donations and seems to be the biggest threat to Trump in New Hampshire. Exit question: How far up the Canadian chain of command does the great Iowa fraud go?

Update: More from Trump on his ground-game failure in Iowa:

“Well, I think we could have used a ground game, a term I wasn’t even familiar with,” he said. “You know, when you say ground game, I say what the hell is that? Now I’m familiar with it. I think in retrospect we should have had a better ground game. I would have funded a better ground game, but you know, people told me that my ground game was fine, and by most standards it was.”

Not true, says Politico. Trump was warned that he needed a better ground game but held off due to the expense.