The Republican debate was very substantive. Too bad that substance was wrong.

Thursday's CNN Republican debate was widely praised for being the most substantive clash of the cycle before. And it was substantive. The only problem was the substance was wrong.

"GDP was zero, essentially, for the last two quarters," said Donald Trump. Only it wasn't. Adjusted for inflation, Gross Domestic Product grew at a 2.1 percent annual rate in the third quarter of 2015 and a 1.9 percent in the fourth quarter.

"We're at zero," Trump continued. "We've lost our jobs. We've lost everything." He said this mere days after the Bureau of Labor Statistics reported that the economy added 242,000 jobs on February — the 72nd straight month of job growth, which is the longest streak of job growth on record.

Trump went on to propose that America's economic problems could be solved by slashing foreign aid and cutting "waste, fraud, and abuse." The moderators turned to Marco Rubio for the rebuttal, and Rubio, to his credit, delivered it. Foreign aid, he noted, is less than one percent of our budget. And waste, fraud and abuse is what politicians promise they'll cut when they have no idea what they'll actually cut. Trump's plan, Rubio said, would leave us with "hundreds of billions of dollars of deficit you'll have to make up."

Marco Rubio's budget promises don't come close to adding up

But even as Rubio presented himself as a paragon of fiscal virtue, his actual platform is a $6.8 trillion tax cut paired with another trillion dollars in increased military spending, and he has never come close to saying how he'll pay for any of it.

To give a sense of scale here, Rubio could cut Medicaid and the Children's Health Insurance Program entirely and only save $4.7 trillion. He could find another trillion dollars by eliminating all education spending: Pell grants, the Department of Education, K-12 funds, school nutrition programs, Head Start — all of it. That gets him to roughly $5.7 trillion.

Knocking out all justice spending could net another $561 billion. But there might be some political resistance to wiping out the FBI, the Drug Enforcement Administration, much of the Department of Justice, all United States attorneys, the entire federal judiciary, and the Federal Bureau of Prisons.

But if Rubio forges ahead, he could get another $540 billion or so by wiping out international spending — so closing all US embassies and consulates around the world, zeroing out all aid to developing nations, ending all military funding for allies, and closing the State Department, among other functions.

All that done, he'd just need to find another trillion dollars to pay for his new military spending. Easy, right?

Cruz: you must destroy Social Security to save it

At that point, the conversation turned to Ted Cruz. "Senator Cruz," the moderator asked, "You advocate allowing younger workers to put some of their Social Security taxes into personal accounts. What do you say to critics who say that market volatility means that this is a disastrous proposal?"

Cruz's reply was almost impressively disingenuous. He ignored the issue of market volatility and instead focused on finances. "Social Security right now is careening towards insolvency, and it's irresponsible," he replied. "And any politician that doesn't step forward and address it is not being a real leader."

Here's what Cruz didn't say: privatizing Social Security makes its near-term fiscal problems worse, not better. As Greg Anrig explained during the debate over George W. Bush's privatization plan, when you move to a system with private accounts, "Funds now being set aside to build up the trust funds to provide for retiring Baby Boomers would be used instead to pay for the privatization accounts. The government would have to start borrowing from the private sector almost immediately to be able to meet commitments to retirees and near-retirees."

There are reasons you might support private accounts in Social Security. But one of those reasons simply isn't that you think the program is near-term insolvent. If you want to close Social Security's funding gap, you don't take money out of the program to create private accounts, you use spending cuts or tax increases to put more money into the program.

John Kasich says he fought Washington insiders to balanced the budget. Nope.

The moderators then turned to John Kasich. "We hear about taking on Washington," he bragged. "I took on Washington and I won. I actually got the budget balanced when I was a member of the Congress, the chairman of the Budget Committee. We paid down a half a trillion dollars of the national debt. We also balanced the budget four years in a row, and we were just growing jobs like crazy, and the wage issue was not even an issue then." He went on to promise to use "the same formula to beat the Washington insiders again."

Kasich didn't take on Washington insiders to balance the budget. The truth is almost literally the opposite. He opposed the deals that led to a balanced budget and then he was one of the Washington insiders that managed to take credit for the balanced budget anyway.

The balanced budget of the late-1990s was the product of three things. The first was the 1990 budget deal, where President George H.W. Bush broke his pledge not to raise taxes, but also got Democrats to agree to huge spending cuts. Kasich voted against that deal. Then there was President Clinton's 1993 tax increase, which Kasich also opposed, warning it would destroy jobs. Finally and most importantly, there was the technology-driven economic boom, which no politician can take credit for.

Kasich was an architect of the 1997 Balanced Budget Act, but the story there was of Washington insiders, of which Kasich was one, cutting a deal that let them take joint credit for economic and budgetary trends that were already in place.

And the band played on...

From there, the moderators turned back to Donald Trump, who began ranting about China devaluing their currency when they are, right now, doing literally the opposite thing.

Later in the debate, Marco Rubio responded to a question on climate change by saying "as far as a law that we can pass in Washington to change the weather, there's no such thing." That is a devastating rebuttal to a position literally no one holds. Then, when pressed further on whether climate change, Rubio said, "I would say there's no law we could pass that would have an impact on that," which is completely and totally false.

So was this debate substantive? Sure, in the sense that it focused on weighty policy topics like Social Security and trade and the assembled candidates mostly used their inside voices. But the things the candidates actually said were, by turns, wrong, misleading, misinformed, confused, or ridiculous. This substantive debate mostly showed how weak a grasp on the issues the candidates actually have.