"The questions that have been asked so far in this debate illustrate why the American people don't trust the media," Ted Cruz said with considerable disgust. "This is not a cage match."

Cruz ticked off the insults the CNBC moderators had lobbed Wednesday night at the assembled Republicans. "Donald Trump, are you a comic book villain? Ben Carson, can you do math? John Kasich, will you insult two people over here? Marco Rubio, why don't you resign? Jeb Bush, why have your numbers fallen? How about talking about the substantive issues?"

The crowd roared. Republican pollster Frank Luntz reported with some awe that his focus group gave Cruz's riff a 98. "That's the highest score we've ever measured," Luntz tweeted. "EVER."

Cruz's attack on the moderators was smart politics — but it was almost precisely backwards. The questions in the CNBC debate, though relentlessly tough, were easily the most substantive of the debates so far. And the problem for Republicans is that substantive questions about their policy proposals end up sounding like hostile attacks — but that's because the policy proposals are ridiculous, not because the questions are actually unfair.

The Republican primary has thus far been a festival of outlandish policy. The candidates seem to be competing to craft the tax plan that gives the largest tax cut to the rich while blowing the biggest hole in the deficit (a competition that, as of tonight, Ted Cruz appears to be winning). And the problem is when you ask about those plans, simply stating the facts of the policies sounds like you're leveling a devastating attack.

Take the question to Trump. He wasn't asked if he was a comic book villain. He was asked why his policies sound like "a comic book version of a presidential campaign." And the question was specific. Moderator John Harwood asked, "Mr. Trump, you have done very well in this campaign so far by promising to build another wall and make another country pay for it. Send 11 million people out of the country. Cut taxes $10 trillion without increasing the deficit."

Trump declined to explain how he could cut taxes by $10 trillion without increasing the deficit. Instead, he appealed to another CNBC personality for support. "Larry Kudlow, who sits on your panel, who's a great guy, came out the other day and said, 'I love Trump's tax plan.'"

As for the wall, Trump didn't get very specific there, either. "A politician cannot get them to pay. I can." That is ... not an answer.

Similarly, Ben Carson wasn't asked whether he could do math. He was asked whether his tax plan's math added up.

"You have a flat tax plan of 10 percent flat taxes," said moderator Becky Quick. "This is something that is very appealing to a lot of voters, but I've had a really tough time trying to make the math work on this. If you were to take a 10 percent tax, with the numbers right now in total personal income, you're gonna bring in $1.5 trillion. That is less than half of what we bring in right now. And by the way, it's gonna leave us in a $2 trillion hole. So what analysis got you to the point where you think this will work?"

The ensuing exchange is worth quoting at length:

CARSON: The rate — the rate — the rate is gonna be much closer to 15 percent. QUICK: 15 percent still leaves you with a $1.1 trillion hole. CARSON: You also have to get rid of all the deductions and all the loopholes. You also have to some strategically cutting in several places. Remember, we have 645 federal agencies and sub-agencies. Anybody who tells me that we need every penny and every one of those is in a fantasy world. So, also, we can stimulate the economy. That's gonna be the real growth engine. Stimulating the economy — because it's tethered down right now with so many regulations... QUICK: You'd have to cut — you'd have to cut government about 40 percent to make it work with a $1.1 trillion hole. CARSON: That's not true. QUICK: That is true, I looked at the numbers. CARSON: When — when we put all the facts down, you'll be able to see that it's not true, it works out very well.

The question was extremely substantive. Carson's answer was laughably vague. The problem here isn't that Carson was asked whether he can do math, but that he couldn't show that his tax plan was based on sound math. And that's because it isn't.

As for the question to Kasich, he was asked about a speech he gave on Tuesday calling his rivals' proposals "crazy." As the New York Times reported, Kasich argued "that Republicans who proposed abolishing Medicaid and Medicare, imposing a 10 percent flat tax, or deporting millions of people were out of touch with reality."

Kasich is right about all that, by the way. And while the question was, as Cruz said, an invitation to attack some of the other candidates, it was keyed to a substantive debate about some very strange policy ideas.

Meanwhile, Cruz himself was also asked a substantive question. The moderators asked why he was opposing a bipartisan budget deal that would avert a debt ceiling crisis, a Medicare crisis, and a Social Security Disability Insurance crisis. Rather than answer that question, he attacked the moderators for refusing to ask substantive questions, during which he pretended a slew of unusually substantive questions were trivial political attacks.

Cruz's strategy was smart, and he was arguably the debate's big winner. But it bespoke a deeper weakness. Republicans have boxed themselves into some truly bizarre policies — including a set of tax cuts that give so much money to the rich, and blow such huge holes in the deficit, that simply asking about them in any serious way seems like a vicious attack. Assailing the media is a good way to try to dodge those questions for a little while, but it won't work over the course of a long campaign.